Banking apps work fine (I’m in the UK). Though HSBC recently started to refuse to run because I have a keyboard app installed from F-droid. But that’ll be a problem on any phone, not specific to Fairphone, I think.

Also seconding mailbox.org, really good. Cheap and does the job perfectly.

There are simple workarounds you can try to fix it, see for example https://github.com/linuxmint/cinnamon/issues/12994#issuecomment-3134995065