Using the Android app, when I change the units on a DS18B20 temperature sensor to Fahrenheit, the value on the dashboard changes, but even I tap on number to view the value history, the units in the history graphs are still in Celsius.
Device: Raspberry Pi model 3 B+, DS18B20 temperature sensor, nothing else connected
Dashboard: Android (Pixel 2 XL, Android 9 January security patch)