Me Too!
In my case metric and 24 hrs are reset upon restarting the app after saving the settings.
Through the web interface (either directly to ip address or through cloud.openthings.io) settings appear to stay set to metric, even when i use a different browser that had not been connected before (suggesting settings are stored correctly in the controller, just not in the app?)
My location stays saved correctly.
I did FORCE STOP the app – no change
I CLEARED CACHE – no change
I CLEARED STORAGE – no change
I had this problem in the previous FW version (I think i was on 2.2.0) and have it in the current version (2.2.1 (1)) as well.
I am using ANDROID app version 2.4.43
Web app version is 2.4.49