Yes I have been having the issue you describe. I have not tried opening the lid though, very interesting.
I've been at home due to the CCP Virus (aka covid), and work provided a Surface Laptop 3. I'm sitting, like you describe, within arms reach, yet audio on my Airpod Pros is horribly choppy, and i cannot walk 5 ft away without disconnecting. Ok, maybe i get 8-10 ft. it's unbelievably bad.
I cannot open my lid all the way, I have a monitor right behind it. but I can prop is half way open. So right now I've done that, and I'm walking out of the room......so it's much better, I made it out of my computer room into the connected family room without losing audio. I was able to go down the hallway, @20', to my kitchen, audio was doing well. As soon as i turned into the kitchen, audio started to break up, and within several steps I'd lost connection. Have returned, clearly as I'm typing, and connection did not restore. Surface still shows connection to Ipods, yet no sound.
Spotify shows still playing as well. Switch sound device to speakers, sound returns, switch back to Airpod Pros and audio returns. So there is definitely an issue. Perhaps MS is mistakenly reducing the BT transmitter power by 80/90% with the lid closed? if so, please update/correct that behavior MS!!