Computrainer issue

I am so fortunate that for the past 15 years my Computrainer has never failed me. Today during the Le Col workout the Wattage reading started going up incrementally until 2000 then back down to 0 and then stabilizing at the desired Wattage for a few minutes and then doing the same thing again. This went on for the entire 40 minute ride. I even got a ZWIFT generated message that stated that I had missed my calling as a pro.
If there are still any Computrainer riders out there have you ever experienced this and what did you do about it.
Calibration perfect.

I wonder if it overheated. Try aiming a fan at it.