[PSA] If you had switched to the main update channel to get 3.5 early, I would recommend changing back one of the less bleeding edge update channels.
SteamOS 3.6 is live on the "main" update channel, and it is very buggy. (Note: the most bleeding edge update channel is called main. 3.6 is only live on the "main" channel, not any of the stable or beta channels).
I had switched to main to get 3.5 early, and 3.5 had spent so much time in the main channel that it's been very stable for the last few months. However 3.6 has been rough, game mode would crash and restart everytime a decky plugin did something, and it broke my desktop mode completely. I've downgraded to beta-candidate (which is still 3.5) and things are much better.
I know that staying off the most bleeding edge update channels if you want a stable experience is common sense, but I think a lot of people got impatient for 3.5 and may have been lulled into a false sense of security by how stable the 3.5 main update builds were recently.
I've been on 3.5 for awhile, and they're working fine for me. I did have an issue where occasionally my TV would reset (go black for a second and then come back on), that I hadn't noticed before on previous SteamOS versions, but searching online makes it seem like that's a problem with Vizio TVs and 4k/HDR, not a SteamOS issue. I was able to duplicate the issue using a 4k Chromecast on the TV, and disabling HDR and capping the resolution below 4k completely fixed the issue when using the Deck with the TV.