I have that issue after the second day using the Q2 . And for two weeks of tweaking . This morning I tried lowering the Encode bit rate to 200 on the Oculus debug tool., Encode resolution width to 3664 and Pixel per display to 1.2.
That's all I did. For some reason It worked on my system. I7 9700K, RAM 64 and RX 6900 XT. So far so good today and I've been testing it on MSFS 2020 and DCS and dammed white strip is gone. Hopefully it will work other sytems too.
This here helped me fix this issue. I've played Tertis effect for 1 hours and I've yet to see the white line return. Before this I would simply get the distortion within 2-5 minutes. I'm rocking a 5600x, 16 GB's of ram, and a 3060ti. further testing is needed to see if the white line comes back however things are looking good.
Edit : While it seemed as thing were alright after playing around the same time as yesterday the distortion start to reappear. as many have stated this doesn't seem to be more than a band aid fix. It DOES seem to keep the issue at bay for at least 30 minutes plus. (which is way better than getting it within the 2-5 minutes.)