UPDATE: Proton 7.06 has been released as the Default version, fixing this issue.
You may have seen some news about a Ubisoft connect update causing crashing on Steam Deck, showing the error below.
Thankfully Valve was quick on the case once again and pushed out a very quick Proton Experimental update which fixed the issue.
Video Guide: https://www.youtube.com/shorts/-_R6uVNy3ho