The app freezes or crashes easily on the ipad. It deletes work of 4 hours. It does not save everytime when exiting a document.

For details:
The app crashes/freezes on existing and on new documents.
Sometimes it crashes after 5 minutes sometimes after 1-2 hours or more.
When it crashes, you have to reopen and close the app 4-5 times before it lets you open a document again.
When exiting a document :“File/Document could not be saved“, practically out of 5 documents it saves 1.