I've enabled an online archive for some users and changed the default name of it in EAC (exchange online obviously). It changed almost instantaniously on the web, but hasn't changed for days on the desktop outlook. How can I fix that? Fixing profiles isn't supported for exchange accounts, new profile didn't fix the issue.
Do you mean the archive mailbox name in Outlook client (online archive- firstname.lastname@example.org) is different from the configuration?
In my research, I’m afraid the archive mailbox display name in Outlook client is hard-coded. Please refer to this KB, it is related Outlook 2010, but I think it is same as other versions: