T-Scan Hawk 2 Losing Scan lines

[[Lo...]]

I've noticed that in the morning my scans are cleaner and easier to achieve and this is in part to all of my scan lines being present and solid, but after a few hours about a quarter of my scan lines disappear entirely. I can still see them present with my eyes but the camera seems to ignore them. I suspect the scanner's temperature to be a cause as it seems to resolve if I unplug the scanner for a while, and the area the lines are missing from is the same half of the scanner that gets pretty warm. Is this common or should I be unplugging the scanner all the time? It's used with enough frequency this might be an issue in the long term.