I mostly use the deck in desktop mode recently as my laptop died and I have it hooked up to a dock with monitor and keyboard.
I'm having a bunch of networking issues lately. Basically the network becomes incredibly unstable after some time and a reboot fixes it. Restarting networking through systemd does not fix the issue. Same with disable / enable networking in the dropdown.
Ping is going as high as 10,000ms where after a reboot it's 14ms and I'm getting 5-15% packet loss.
The router is about 7 metres away (22 feet or so).
I do suspend quite a bit. System is fully up to date. Just rebooted and now it's fine.
Even with the reboot, it could still be that the IP is renewed, it would help if you could find out how frequently it happens. What kind of router are you using?
I would recommend disabling wifi battery optimization. I know you can do it from settings in game mode, I'm guessing there may also be a KDE setting for it.