Saving / reopen data loss

Problem

whiteboard data is loss during saving or loading

Story

Hi,
I recently installed ubuntu VM on proxmox, installed docker and started the AIO container nextcloud. I enabled whiteboard but started losing data once in a while for unknown reason. I suspected my proxy and cloudflare settings, so I bypassed cloudflare, but still the problem persisted.
I disabled whiteboard in AIO because I suspected redis database, so I created a container manually as per the manual and created a proxy location redirect as written, in nextcloud administration everything seems ok and connected.
But the exact same problem occurred as when hosting in mastercontainer, but now I was running on LRU Cache, so that ruled it out. I was unable to replicate the error for sometimes several dozens of minutes.
After some time, I noticed that when I have a maximized window on my main monitor, the data loss happens almost immediately, while when I have a whiteboard window open in a smaller window on the other monitor, it failed to replicate.

Suspicions and replication

Is it possible that the data loss that is being addressed below is not caused by the socket or cashing or database, but by the resolution or some monitor parameter ( or changing it ? )
The video below shows the data loss in live, at the beginning you can see the window in full resolution, that the loss occurs right away the second time, after changing the resolution to smaller then everything works as it should, then I put the resolution back and almost immediately the loss occurs again.
You can also see the console that the save occurs, but after loading the log shows that it contains no data.

Tried

• cloudflare bypass
• AIO master container included whiteboard
• self created whiteboard container with socket.io proxy forwarding
• different proxy location configurations

Maybe related open issues?

#382
#358
#348

Output

Same problem, could not fixed myself

Setup

Proxmox

Ubuntu VM

Docker

AIO nexcloud ( with whiteboard )
( only whiteboard container )

Monitor setup

1 - 2560 x 1440
2 - 1080 x 1920
3 - 3440 x 1440

Video

17s - fullscreen monitor_1 data loss, switched to floating window an window moved to monitor_3
26s - 52s - no problem working with whiteboard, then switch back to monitor_1
1:06 - second dala loss on monitor_1

https://github.com/user-attachments/assets/c875f77b-89e4-46aa-8efc-f0395c4282fe