Don't have a Snap but when I used to have fluid trainers I'd point a fan at the resistance unit and angle it such that it'd also get some airflow where the tire makes contact on the roller. Mainly did it so the the resistance unit wouldn't overheat and destroy the seals. The one time I forgot to turn on that fan sure enough fluid leaked out (this was an older first gen CycleOps Fluid2).

I've since upgraded from new gen Fluid2 to a direct drive smart trainer. But I still point that fan at the resistance unit to help keep it from overheating. Might help your situation of the Snap getting way too hot.

Curious if perhaps it recalibrated at a higher resistance then you were used too, could happen if a spin-down was prematurely terminated or somehow messed up. I'd check tire pressure/contact, do a full power cycle/reset, re-pair, warm it up for a few minutes, and then do a full spin-down calibration and see if it feels more normal.

If that doesn't fix it, I suppose something could be messing up in the resistance unit. I'd start with Wahoo customer support. They were really helpful when my Kickr went on the fritz and walked me though a repair.