Update Steam Deck and Steam: Make sure both of your Steam Decks are running the latest updates for SteamOS and Steam itself. Sometimes, issues are resolved with the latest patches and updates.

Check Network Connection: Ensure both devices have a stable and strong internet connection. Lag or connectivity issues can sometimes cause problems with Remote Play Together.

Verify Game Compatibility: Not all games support Remote Play Together equally well. Double-check if the game you're trying to play is known to have issues with Remote Play Together or if it requires specific settings.

Adjust Streaming Settings: Go to Steam settings on both devices and adjust the streaming settings. Lowering the streaming quality or resolution might help resolve issues with video and audio.

Clear Cache and Restart: Try restarting both Steam Decks and clearing any cache or temporary files related to Steam or Remote Play Together.

Check for Conflicting Software: Ensure that no other applications or services that might interfere with the streaming are running on either device.

Reinstall Steam: As a last resort, you might consider reinstalling Steam on both Steam Decks. This can help resolve any software corruption issues that might be causing the problem.

Consult Steam Support: If none of the above solutions work, it might be worth reaching out to Steam Support. They may have more specific troubleshooting steps or be able to identify if there’s an underlying issue with the Remote Play Together feature itself.