Shelly H&T flipping from F to C

I have a few Shelly devices, big fan, using the native integration. My H&Ts started reporting Celsius temperatures with Fahrenheit units (ie 8F when it’s above freezing). I figured the integration has been updated to assume reports in C, so I removed the devices, renamed them to avoid old entity collision, and set them to C. Rediscovered, everything is great…

Until a little later when it reverts all over again… anyone know what’s up?