Microsoft To Do Problem

Hallo, 

I have the following problem.

I have a list of "current" in my Microsoft To Do app.

The list contains open and completed entries. Recently, the open entries have suddenly disappeared. I noticed it for the first time on my computer.

When I opened the app on my iPad, I saw the entries briefly and then they were gone - probably after the synchronization. I only see the completed tasks...

This is extremely annoying. How can I get them back?

Kind regards.