Incorrect remote desktop mode mouse mapping on Linux X11/i3wm since v2025.628.4510

Nobody has claimed this yet.

### Is there an existing issue for this?

- [x] I have searched the existing issues

### Is your issue described in the documentation?

- [x] I have read the documentation

### Is your issue present in the latest beta/pre-release?

This issue is present in the latest pre-release

### Describe the Bug

**TL;DR, the mouse is stuck in the second quadrant since `v2025.628.4510`,**

I'm using Sunshine on my Arch Linux mostly for remote desktop purposes, so I usually use it with the "Optimize mouse for remote desktop instead of games" enabled in Moonlight. This way the sensitivity and mouse acceleration are the same on both the remote and the local machine.

Everything worked fine on the previous version `v2025.122.141614`. However, since upgrading to `v2025.628.4510`, without configuration changes, my mouse in remote desktop mode can no longer move out of the second quadrant. To illustrate this better, the mouse cannot be moved out of the unshaded area shown below

This seems to be a scaling issue where the mouse movement area is 1/2 of the actual screen area on both axis, causing it to only occupy the second quadrant.

I tried to look into the code to identify where the issue may be but I have yet found anything that looks like the source of this issue. I also tried upgrading to `v2025.829.135256` and using other packages on the AUR like `sunshine-bin`, but they don't make a difference. Downgrading to `v2025.122.141614` does fix this issue so I think the issue is within the code, not in packaging.

### Expected Behavior

The mouse should be able to move across the entire display normally.

### Additional Context

Client is Windows 11, running Moonlight Qt 6.1.0.

### Host Operating System

Linux

### Operating System Version

Arch Linux x86_64 6.16.7-arch1-1

### Architecture

amd64/x86_64

### Sunshine commit or version

2025.628.4510-6

### Package

Linux - LizardByte/pacman-repo

### GPU Type

NVIDIA

### GPU Model

NVIDIA RTX A1000

### GPU Driver/Mesa Version

580.82.09

### Capture Method

X11 (Linux)

### Config

```Shell
controller = disabled
native_pen_touch = disabled
```

### Apps

```json

```

### Relevant log output

I don't think the log is relevant so I'm folding it to reduce the clutter.

Click to expand logs

```shell
[2025-09-19 01:43:07.236]: Info: Sunshine version: 0.0.0.65f14e1003f831e776c170621bd06d8292f65155
[2025-09-19 01:43:07.236]: Info: Package Publisher: LizardByte
[2025-09-19 01:43:07.236]: Info: Publisher Website: https://app.lizardbyte.dev
[2025-09-19 01:43:07.236]: Info: Get support: https://app.lizardbyte.dev/support
[2025-09-19 01:43:07.236]: Info: config: 'controller' = disabled
[2025-09-19 01:43:07.236]: Info: config: 'native_pen_touch' = disabled
[2025-09-19 01:43:07.236]: Info: config: 'sunshine_name' = Kolibri
[2025-09-19 01:43:07.271]: Info: System tray created
[2025-09-19 01:43:07.455]: Info: Found [1] outputs
[2025-09-19 01:43:07.455]: Info: Virtual Desktop: 3440x1440
[2025-09-19 01:43:07.455]: Info: XrandR: available
[2025-09-19 01:43:07.455]: Info: -- Output --
[2025-09-19 01:43:07.455]: Info: Resolution: 3440x1440
[2025-09-19 01:43:07.455]: Info: Offset: 0x0
[2025-09-19 01:43:07.479]: Error: Couldn't release NvFBC context from current thread:
[2025-09-19 01:43:07.479]: Info: Detecting displays
[2025-09-19 01:43:07.481]: Info: Detected display: DP-0 (id: 0)DP-0 connected: true
[2025-09-19 01:43:07.481]: Info: Detected display: DP-1 (id: 1)DP-1 connected: false
[2025-09-19 01:43:07.481]: Info: Detected display: DP-2 (id: 2)DP-2 connected: false
[2025-09-19 01:43:07.481]: Info: Detected display: DP-3 (id: 3)DP-3 connected: false
[2025-09-19 01:43:07.481]: Info: Detected display: DP-4 (id: 4)DP-4 connected: false
[2025-09-19 01:43:07.481]: Info: Detected display: DP-5 (id: 5)DP-5 connected: false
[2025-09-19 01:43:07.481]: Info: Detected display: DP-6 (id: 6)DP-6 connected: false
[2025-09-19 01:43:07.481]: Info: Detected display: DP-7 (id: 7)DP-7 connected: false
[2025-09-19 01:43:07.488]: Info: // Testing for available encoders, this may generate errors. You can safely ignore those errors. //
[2025-09-19 01:43:07.488]: Info: Trying encoder [nvenc]
[2025-09-19 01:43:07.488]: Info: Screencasting with NvFBC
[2025-09-19 01:43:07.565]: Info: Creating encoder [h264_nvenc]
[2025-09-19 01:43:07.565]: Info: Color coding: SDR (Rec. 601)
[2025-09-19 01:43:07.565]: Info: Color depth: 8-bit
[2025-09-19 01:43:07.565]: Info: Color range: JPEG
[2025-09-19 01:43:07.643]: Info: Streaming bitrate is 1000000
[2025-09-19 01:43:07.905]: Info: Creating encoder [hevc_nvenc]
[2025-09-19 01:43:07.905]: Info: Color coding: SDR (Rec. 601)
[2025-09-19 01:43:07.905]: Info: Color depth: 8-bit
[2025-09-19 01:43:07.905]: Info: Color range: JPEG
[2025-09-19 01:43:07.905]: Info: Streaming bitrate is 1000000
[2025-09-19 01:43:08.168]: Info: Creating encoder [av1_nvenc]
[2025-09-19 01:43:08.168]: Info: Color coding: SDR (Rec. 601)
[2025-09-19 01:43:08.168]: Info: Color depth: 8-bit
[2025-09-19 01:43:08.168]: Info: Color range: JPEG
[2025-09-19 01:43:08.168]: Info: Streaming bitrate is 1000000
[2025-09-19 01:43:08.175]: Warning: [av1_nvenc @ 0x566bab976080] Codec not supported
[2025-09-19 01:43:08.175]: Error: [av1_nvenc @ 0x566bab976080] Provided device doesn't support required NVENC features
[2025-09-19 01:43:08.427]: Error: Could not open codec [av1_nvenc]: Function not implemented
[2025-09-19 01:43:08.457]: Error: Couldn't release NvFBC context from current thread:
[2025-09-19 01:43:08.457]: Info: Screencasting with NvFBC
[2025-09-19 01:43:08.526]: Info: Creating encoder [hevc_nvenc]
[2025-09-19 01:43:08.526]: Info: Color coding: SDR (Rec. 709)
[2025-09-19 01:43:08.526]: Info: Color depth: 10-bit
[2025-09-19 01:43:08.526]: Info: Color range: JPEG
[2025-09-19 01:43:08.526]: Info: Streaming bitrate is 1000000
[2025-09-19 01:43:08.545]: Error: cuda::cuda_t doesn't support any format other than AV_PIX_FMT_NV12
[2025-09-19 01:43:08.816]: Error: Couldn't release NvFBC context from current thread:
[2025-09-19 01:43:08.816]: Info:
[2025-09-19 01:43:08.816]: Info: // Ignore any errors mentioned above, they are not relevant. //
[2025-09-19 01:43:08.816]: Info:
[2025-09-19 01:43:08.816]: Info: Found H.264 encoder: h264_nvenc [nvenc]
[2025-09-19 01:43:08.816]: Info: Found HEVC encoder: hevc_nvenc [nvenc]
[2025-09-19 01:43:08.817]: Error: Failed to create client: Daemon not running
[2025-09-19 01:43:08.818]: Info: Configuration UI available at [https://localhost:47990]
[2025-09-19 01:43:20.706]: Info: // Testing for available encoders, this may generate errors. You can safely ignore those errors. //
[2025-09-19 01:43:20.706]: Info: Trying encoder [nvenc]
[2025-09-19 01:43:20.706]: Info: Screencasting with NvFBC
[2025-09-19 01:43:20.839]: Info: Creating encoder [h264_nvenc]
[2025-09-19 01:43:20.839]: Info: Color coding: SDR (Rec. 601)
[2025-09-19 01:43:20.839]: Info: Color depth: 8-bit
[2025-09-19 01:43:20.839]: Info: Color range: JPEG
[2025-09-19 01:43:20.839]: Info: Streaming bitrate is 1000000
[2025-09-19 01:43:21.102]: Info: Creating encoder [hevc_nvenc]
[2025-09-19 01:43:21.102]: Info: Color coding: SDR (Rec. 601)
[2025-09-19 01:43:21.102]: Info: Color depth: 8-bit
[2025-09-19 01:43:21.102]: Info: Color range: JPEG
[2025-09-19 01:43:21.102]: Info: Streaming bitrate is 1000000
[2025-09-19 01:43:21.366]: Info: Creating encoder [av1_nvenc]
[2025-09-19 01:43:21.366]: Info: Color coding: SDR (Rec. 601)
[2025-09-19 01:43:21.366]: Info: Color depth: 8-bit
[2025-09-19 01:43:21.366]: Info: Color range: JPEG
[2025-09-19 01:43:21.366]: Info: Streaming bitrate is 1000000
[2025-09-19 01:43:21.373]: Warning: [av1_nvenc @ 0x7f5559141c40] Codec not supported
[2025-09-19 01:43:21.373]: Error: [av1_nvenc @ 0x7f5559141c40] Provided device doesn't support required NVENC features
[2025-09-19 01:43:21.625]: Error: Could not open codec [av1_nvenc]: Function not implemented
[2025-09-19 01:43:21.657]: Error: Couldn't release NvFBC context from current thread:
[2025-09-19 01:43:21.657]: Info: Screencasting with NvFBC
[2025-09-19 01:43:21.732]: Info: Creating encoder [hevc_nvenc]
[2025-09-19 01:43:21.732]: Info: Color coding: SDR (Rec. 709)
[2025-09-19 01:43:21.732]: Info: Color depth: 10-bit
[2025-09-19 01:43:21.732]: Info: Color range: JPEG
[2025-09-19 01:43:21.732]: Info: Streaming bitrate is 1000000
[2025-09-19 01:43:21.751]: Error: cuda::cuda_t doesn't support any format other than AV_PIX_FMT_NV12
[2025-09-19 01:43:22.021]: Error: Couldn't release NvFBC context from current thread:
[2025-09-19 01:43:22.021]: Info:
[2025-09-19 01:43:22.021]: Info: // Ignore any errors mentioned above, they are not relevant. //
[2025-09-19 01:43:22.021]: Info:
[2025-09-19 01:43:22.021]: Info: Found H.264 encoder: h264_nvenc [nvenc]
[2025-09-19 01:43:22.021]: Info: Found HEVC encoder: hevc_nvenc [nvenc]
[2025-09-19 01:43:22.021]: Info: Executing [Desktop]
[2025-09-19 01:43:22.081]: Info: New streaming session started [active sessions: 1]
[2025-09-19 01:43:22.091]: Info: CLIENT CONNECTED
[2025-09-19 01:43:22.223]: Info: Found [1] outputs
[2025-09-19 01:43:22.223]: Info: Virtual Desktop: 3440x1440
[2025-09-19 01:43:22.223]: Info: XrandR: available
[2025-09-19 01:43:22.223]: Info: -- Output --
[2025-09-19 01:43:22.223]: Info: Resolution: 3440x1440
[2025-09-19 01:43:22.223]: Info: Offset: 0x0
[2025-09-19 01:43:22.246]: Error: Couldn't release NvFBC context from current thread:
[2025-09-19 01:43:22.246]: Info: Screencasting with NvFBC
[2025-09-19 01:43:22.323]: Info: Creating encoder [h264_nvenc]
[2025-09-19 01:43:22.323]: Info: Color coding: SDR (Rec. 601)
[2025-09-19 01:43:22.323]: Info: Color depth: 8-bit
[2025-09-19 01:43:22.323]: Info: Color range: MPEG
[2025-09-19 01:43:22.324]: Info: Streaming bitrate is 47788000
[2025-09-19 01:43:22.361]: Info: Minimum frame time set to 11.7647ms, based on client-requested target framerate 85.
[2025-09-19 01:43:22.586]: Info: Setting default sink to: [sink-sunshine-stereo]
[2025-09-19 01:43:22.586]: Info: Found default monitor by name: sink-sunshine-stereo.monitor
[2025-09-19 01:43:22.613]: Info: Opus initialized: 48 kHz, 2 channels, 512 kbps (total), LOWDELAY
```

No source file or test is identified in the report. Start by reproducing the issue in Sunshine's X11 remote-desktop mouse mode with the listed versions and configuration, then trace the mouse-coordinate mapping; done means the pointer can move across the entire 3440x1440 display rather than remaining in the second quadrant.

Written by the indexing model from the issue text.