Screenshare ignores the selected codec and drops to low resolution when other users are in the call

Observed behaviour

The stream defaults to the H264 codec, regardless of whether or not it was picked, regardless of whether or not the fallback was enabled. Additionally, the quality randomly becomes over time or immediately 270p, with only ~10% of so of attempts being 720p, and for a limited time before degrading. (affects both desktop and web versions)

Reproduction steps

Join a non-empty voice chat (note that it must be two or more different users, it CANNOT be a single user on multiple devices)
Stream

Build information

Canary Desktop 2026.527.223435, Web 2026.529.110914, Linux 7.0.10-2-cachyos (x64), Electron 41.2.2, Chrome 146.0.7680.188, Node 24.14.1, Locale en-US

Platform

Linux

Details

Expected behaviour The picked codec should correspond to the one in Audio & Video settings, as it does when alone in an empty voice chat.