Can't change any configuration on iOS version

Fiddling with configuration settings on Joplin on my iPhone I noticed that none of the changes I make ever "sticks."

I change Theme to 'Dark', nothing happens, leave the screen, come back to Configuration, and the theme is back to 'Light'

I change language to French, go back to notes, language remains English, go back to Configurations, language setting is back to English.

It's almost as if the Configuration screen wants me to click "Apply" or "Save" in order to register changes. But there is no such option on the screen.

Is anyone else experiencing this?

Joplin 10.4.1
iOS 14.2