Hi there, I've been testing it over and over again and it just works for me. C to F and vice versa.
@justliknoah and @DigiGirlFL please also check this list of layers for which you need to change & save preferred units in the desktop version (then they will sync with your app) :
https://community.windy.com/topic/5578/overview-of-units-used-on-windy