TPMS light only when cold, not tires...??

[O5Q45]

After a very Intense 80 mile, in 9 inches of snow going over the Blueridge mountains to Asheville at 4am for work, my TPMS light came on and when I check the "info" in the car I get a reading of all astricks instead of tire pressure amounts. All ****
After shutting off the ignition it resets. If it's warmer than 40°f, no light.
I know I reach 3700ft elevation at the gap on the mountain every morning, and normally 1°-28°f in winter months..
Why all astricks and no indication of which tire or sensor issue? Tires are compensated for cold temp/pressure fluctuations

[Aquaholic21]

I would start with a good underbody wash...mine does that when the sensors get dirty.