Weird. Works now. But, I had to go through the Steam/Power menu. Now it works via holding the power button instead of doing nothing.

EDIT: Spoke too soon. Power button not working again. Power menu not working either.

theres bug with deck/compat, and also using 3rd party hardware which steam initial said they supported but retracted so its a user problem or 3rd prblem f up, either which u should put in ticket depending on ur isssue

Are you using Beta or Stable?

Yeah I've just been trying figure this out.

The fix is to just go back to stable as beta and preview seems to be broken

I'm using beta. A reboot followed by using the Steam/Power menu to enter desktop mode seems to work consistently for me.

I had the same issue, I just had to reboot a few times also. Good to know its not just me.

I had that issue, I just went back to stable instead of Beta.

Same happening for me on the latest beta update (OS version 3.3.2 OS build 20221005.1). Switching from Beta back to Stable fixed it.

Yup, same issue and workaround works

Looks like it's fixed with the latest beta update.

Indeed, works again after the update

having a similar issue, using the side menu, but mine shuts off upon selecting switch to desktop mode, what the jell is this

Sadly, this is the same for me since the last Firmware upgrade (approximately one week ago). I changed one of my non-steam entry so it starts konsole which allows me to start everything else I would have used in desktop mode, such as okular.
Nevertheless: any other option to actually use the desktop mode again would be very welcome. Any ideas?

I could fix the issue by disabling bluetooth everytime before switching between desktop/gaming mode (for now)

It's a really annoying bug indeed

I'm on beta branch

It would be an understatement to say that I was skeptical that turning of bluetooth would solve that problem, but it sure did! Thanks a million!