Hi Philipp Neubert Thank you for posting to the Microsoft community. Based on the description, you are having an issue on your Microsoft loop page that suddenly disappeared.
I'm so sorry to hear this kind of issue ,this is not the experience we want you to have. I can imagine how inconvenient this must be for you.
In this case, it would be better to submit a feedback regarding on this matter especially in public documentation about data restore for Loop.
During this preview we want to hear from you to help improve your experience – so send us your feedback in the app to help us shape the journey. In the bottom right corner, select Help > Give feedback.
Than you for understanding. Truly Yours,FatimaMicrosoft Moderator