Hi Adster,
Have you checked if your browser allows links to open pop ups, it will be in security settings of your browser..in my case Edge settings didn't allow pop ups to open from links.
Plus my online file was still on version 2025.8 while the desktop version was on 2026.1
Support had to manually run a script on the online file to match versions.
I agree maybe Beta testing went well but there are so many configurations possible on pc/s laptops etc....and this upgrade, just like the last few by MYOB has caused endless grief. My 90 minutes lost yesterday has meant starting work today at 5:00am to catch up...and now I find my wife can't log into her file even though it worked OK when I left home :)
and...if I recall I wasn't asked for 2FA today as well.....