Mail not syncing properly on iPad mini
I have 2 mail accounts which sync mail through IMAP. I use these mail accounts on my iPad mini, iPhone 11 Pro and MacBook.
In recent times, it happened repeatedly that the iPad synchronisation failed partially. Some mails I delete on the iPad are not synchronised with the mail server and so not visible on the iPhone or MacBook. A couple of times, I deleted the account, rebooted the iPad and created the account again. This resolves the sync issue for a couple of days/weeks until it reappears. I also tried to setup the iPad from scratch and restore all data from iTunes backup. Same situation.
The iPhone and MacBook have no issues. So it has to be related to the iPad. Any ideas how to resolve this?
iPad mini 5 Wi-Fi