Using New Outlook on Windows for professional communication and productivity
I have found a second workaround:
to delete all email accounts and old informations in the new outlook, I deleted the folder
C:\Users*username*\AppData\Local\Microsoft\Olk
After I started the old Outlook once and switched from there to the new one. that way, I got a clean new outlook and could reconnect my accounts again and the settingspage is back too
This workaround is working now for me on New Outlook! Thanks Grit for sticking with it.