FYI:I also have the same problem using OAK-D on Linux Mint 20.2. It is also occurs guided+manual_test and any EXAMPLE I ran, x, y, z= zero.
On my Pi 4 I was a unable to run the depthai_demo GUI. When I ran it 2 screens were displayed, color and depth x, y, z= zero. Also, any EXAMPLE I ran, x, y, z= zero.
Pi 4 system, 8GB RAM, 32GB SD card, Buster OS full update.
Looking forward to trying out your fix...