Can't add categories


Have just recently download the app on iOS and loving it so far. I’d like to add information for a product, but I can’t seem to add categories. When I tap ‘Add missing product category’, it brings up the page and I type in the autocomplete box and tap a suggestion, which then appears to be added to the list below with a trash icon next to it. But when I then go to click ‘save’ nothing happens. The same if I try to exit the page - ‘save’ doesn’t work but ‘discard changes’ does.

Apologies if I’m doing something wrong here!