Hi ,
Similar to OP, I noticed the are grids of red and green, visible only on the right eye of the HMD.
The artifacts are not displayed if the HMD loses tracking (all-grey).
I always unplug the power going to the link box if the HMD is not being used.
Sometimes I get the artifacts straight away after starting SteamVR, and sometimes it took around ~5 minutes in SteamVR Home for the artifacts to be displayed.
Once the problem manifests, it wont go away until after I unplugged the power for a few days.
But 80% of the time, I'm seeing it right away after getting to SteamVR Home.
What I have already tried:
Bypassed the link box and connected the HDMI and directly to the GPU and USB directly to PC, the problem still persists.
I purchased a new 3-in-1 cable, and connected through that, the problem is still there.