B-frames not setting to 0 despite logging so

Operating System Info

Windows 10

Other OS

No response

OBS Studio Version

29.1.3

OBS Studio Version (Other)

No response

OBS Studio Log URL

https://obsproject.com/logs/8L3AQcoToTitkydX

OBS Studio Crash Log URL

No response

Expected Behavior

B-frames should be set to 0 when incompatible as the log implies.

Current Behavior

This is shown in the log

16:52:57.892: [jim-nvenc] Max B-frames setting (2) is more than encoder supports (0).
16:52:57.892: Setting B-frames to 0

But the output settings still show b-frames set to 2 and the encoder fails to start.

16:52:57.908: [FFmpeg NVENC encoder: 'simple_video_recording'] settings:
16:52:57.908: 	encoder:      NVIDIA NVENC HEVC (FFmpeg)
16:52:57.908: 	rate_control: CQP
16:52:57.908: 	bitrate:      0
16:52:57.908: 	cqp:          18
16:52:57.908: 	keyint:       250
16:52:57.908: 	preset:       p5
16:52:57.908: 	tuning:       hq
16:52:57.908: 	multipass:    qres
16:52:57.908: 	profile:      main
16:52:57.908: 	width:        852
16:52:57.908: 	height:       480
16:52:57.908: 	b-frames:     2
16:52:57.908: 	psycho-aq:    1
16:52:57.908: 	GPU:          0

The user reporting this was able to start their encoder after switching to advanced output mode and manually setting b-frames to 0.

Steps to Reproduce

1. Start recording on simple output mode with this users hardware
2. B-frames being set to 0 is logged but the encoder is still unable to start

Anything else we should know?

This is not my hardware, I am reporting on behalf of someone in the support discord.

Review the simple output mode path for the FFmpeg NVENC encoder and compare the logged B-frame fallback with the final output settings. Use the linked OBS log and the reported hardware configuration if available; done when unsupported hardware starts recording with B-frames at 0 without manual advanced-mode changes.