Shelly Plus H&T gets confused between F and C after restarting HA

I have a new Shelly Plus H&T (using batteries), and I have it integrated using the standard Shelly integration. Everything works great unless I restart HA. Based on the data, it looks like the Shelly integration always thinks the stored temp is in C. For example, if I restart when the temp is 73F, the after-restart temp will show as 163.4F (which is 73C converted to F). If I restart again, it jumps up to 326.12, and that continues until the H&T wakes up and sends a new value.

I tried adding an entry in customize, but that didn’t change anything.