Please mention whether you’re on stable, beta, or a different update channel. There’s a good chance most bugs on the stable update channel have been fixed already, so anyone on the beta update can let people know if the bug they’re facing is already fixed.
There was a bug with that, caused both by Decky Recorder and by having Valve’s own game recorder turned on. Uninstalling Decky Recorder and making sure the built in recorder is turned off before entering desktop mode seems to fix it.