Yeah definitely wierd & I hope that Valve is aware so it could be fixed

Just want to add to this, I am also having this issue. I have a Steam Deck LCD & my partner just got me a Steam Deck OLED LE. After hooking up my new OLED to the dock I was prompted to update the dock firmware. Since then, I have been unable to get above 30fps when docked. Tried a few different things, going into desktop mode & checking the TV’s refresh rate, changing resolution in game properties on Steam before launching & nothing works. This appears to be a new issue & glad I’m not the only one! I was starting to worry and was thinking maybe the new Deck OLED was the issue