After recently releasing a big Stable Steam Client update for Steam Deck and Desktop PCs, I highlighted that Remote Play was broken on Steam Deck - and so Valve has now fixed it.
This particular change would just be for the steam deck, since it is a steam deck client update.
It might be worth taking a look at the steam link community on steam. I saw a valve employee trying to help people diagnose issues in one of the pinned posts on the Android community.