
I figured it out.
It is a display language problem, and a bug affecting profiles with norwegian language.
Solution/Workaround:
Go to myaccount language settings:
https://myaccount.microsoft.com/settingsandprivacy/language
Change language from norwegian to english.
To confirm the change is working, open a InPrivate browsing window (or clear all browser cache immediately). Then log in to https://admin.microsoft.com again. Should now be working, but be in english.
PS: During my troubleshooting with MS, we also tried getting another admin at my company (with english settings) to revoke and reinstate my admin membership. As far as I know, this changed nothing, but I cannot be certain of that.
Edit: As Kim Sandbekkbråten already pointed out, the issue is now resolved. I got a callback on my ticket today, and confirmed the solution for me as well. So it should be safe to switch language back if you want. If anyone comes across this thread in the future with similar issue : get in touch with the support number on this link : https://learn.microsoft.com/en-us/microsoft-365/admin/support-contact-info?view=o365-worldwide#norway - they have been very helpful with me. Also worth noting: During our remote troubleshooting, I did show the support agent this discussion thread to show that this was an issue affecting more than just me, and that the common denominator was the country (and therefore maybe language settings). Seems they did take notice of this discussion and watched the thread after that. Point being: even if you do not have anything more to contribute to the discussion than just a "hey, I have the same problem too!, and this is what i tried to fix or do as workaround with no luck" - it is helpful in narrowing down the scope of affected users.
- @Anonymous would you mind marking this answer as correct, to show the issue is resolved?