Multiple documents

[Arnor48]

As a Planmaker user, I recently experienced working with multiple documents. The names of open documents were neatly displayed in a bar and could be clicked to continue working with them.

For a few weeks now, I've been unable to do this. After opening a first document and seeing its contents in the window, I try to open a second document via Open. However, nothing happens. I don't see the contents of this second document. The bar with document names doesn't appear either.

I use a Lenovo tablet running Android 15. What could be wrong with this?