Have you tried playing around with remote play settings both on the host PC and the deck? I had some issues with it myself, even when on 5G wifi that is on the same LAN as the host, which is connected by wire, until I did some tinkering.

Enable hardware encoding, and HEVC codec, on the host.

On the deck, enable HEVC, but keep the hardware decoding disabled, and limit the client resolution to Deck’s screen (1280x800) and limit the max FPS to 60, and keep bandwidth limit to auto.

But If you are dead certain that you want to use the 3rd party streaming, Moonlight client on the Deck + Sunshine server on the host seems to be the most popular option to go for, as Sunshine supports both AMD and Nvidia cards

Is there any way to bind the Discord’s PTT to gamepad buttons without mapping them to emulate a keyboard button press?

How do you use Discord on Deck, exactly? Not having Discord is literally the last thing that stops me from playing most coop games with my friends using Deck, because games either lack VoIP or we just use discord most of the time.

Well, after trying everything I could think of to at least narrow down the possible cause, I’ve decided to reinstall SteamOS without wiping the data, and it fixed the issue. So, I dunno what it was, but now it’s gone.