Mine is on the dashboard, side mirror and main screen (where ever it shows when reversing in normal operating mode) Also happens when using the right side turn signal.I had this exact same issue on the driver's side sideview mirror camera feed. Dealership diagnosed it as a problem with the door wiring/wire harness. They replaced the wire harness and I have not had any issue since. I have put on 510 miles since the fix.
Had the door latch on the passenger side replaced and it was fine for a while and then the cameras got worse.....took it into the dealership after talking to Kia Consumer Affairs saying they had found a solution to fix it - dealership advisor couldn't really tell what they did but it had to do with a cable they ran thru the passenger side and it is FIXED.....week to a week and half my cameras went out again fluttering, gray no picture to clearly see anything......they have my car now at the dealership and am hopeful they will resolve this.......they have offered to do a trade in on this Telluride for a new one? Really don't know what to do - I LOVE my working Telluride!!