Tire Temperature and Wear Graphics Grayed Out

I'm running the 60's mod and the graphical representations of the tire temperatures and wear are grayed out some sessions. This happens both on- and off-line, and with invulnerability both set and not set. The temperature numbers are still good, and update live, though. I don't know what else to report. Is there a button or keypress that activates/ deactivates it?

 

It's a known bug with any and all cars on any and all tracks, and seems to be completely random.