I have the latest firmware (.6810.) installed on the Quest and the guardian walls always pop up when I stretch both arms to the opposite sides at the same time while looking ahead. When I look to the sides stretching my arms the walls don't appear.
Can anyone reproduce this behaviour and is there a solution (except waiting for the next firmware updates)?
If the guardian pops up when he has his arms like that, then they'll pop up playing Beat Saber. I have the same issue. Suddenly, my 7x7 actual play area, that was good enough for my Rift, is too small for my Quest. 😛
I also noticed the guardian pops up when I swing both arms down and slightly behind myself. This can also happen in Beat Saber. So probably every time when both controllers disappear at once out of the tracking cameras view the walls pop up, no matter how big your play space is.