Onenote will not open on Samsung Android phone

For the past 2 months I have not been able to open Onenote on my Samsung S8 phone.

I have followed historical advice I found by clearing the cache, uninstalling, restart and then reinstall from the Playstore. This works the first time I open Onenote, but I am not able to reopen after this. All I get is a start up screen with the purple square in the middle and Microsoft at the bottom.

Can anyone help.