Welcome and thanks for reaching out to the Community, @marcschiller.
Logging into QuickBooks Online (QBO) shouldn't require you to rest password as long as the credentials you've entered are correct. To isolate this, try signing into your account using a private browser (incognito). There are times that the browser is full of frequently accessed page resources, causing some unusual responses.
Press Ctrl + Shift + N (Google Chrome).
Ctrl + Shift + P (Firefox or Internet Explorer).
Control + Option + P (Safari).
If it didn't ask to reset the password, go back to the default browser and perform a clear cache. Every so often, the cache becomes overwhelmed with older data, which can potentially cause viewing and performance issues. Clearing it will refresh the system, and you'll be able to work with a clean slate.