Can't connact via Android Outlook App to Outlook 365 account

Hello,

I changed from a Lumia phone to Android. To sync my contacts and calendars I installted the Microsoft Outlook App. But I can't conntact. My email adress from my microsoft account is "contact@derwelle.de" the same for my office 365 account. When I enter this email adress in the outlook app and select office365 in the next stept the app tell me in the next login screen: ".derwelle isn't in our system. Please make sure you spelled the name correctly" (translated from German). But in the text field below stand my write name "contact@derwelle.de".

A Login in the browser isn't a problem. I also connected more then 10 other microsoft apps with my account and also the word, excel and outlook app to my office365 account.

I also tried the email adress which stands in the browser near my foto in the rigt top edge "outlook_77C88E[...]4D@outlook.com" but there is the message "This account is not existing".

I contact the microsoft hotline for more than a hour but there was no solution.