PowerPoint freezing, and losing data on save. IPad Pro 5th gen, 12.9 WiFi

Hi! I did a couple of searches on here but one problem is that I lack the knowledge of how to characterize what is happening in a specific way.

I recently purchased a fifth generation iPad Pro 12.9 inch to use in order to write over PowerPoint presentations in order to take notes in class. I’m having issues with trying to save the marked up versions of my PowerPoint presentations. Sometimes whether using auto save or saving it manually to my iPad PowerPoint freezes up on the ‘saving’ dialog box. The only option I have in that box is ‘cancel’, but if I click that it still continues to freeze or thrash and it gets stuck that way until I reboot the iPad. Worse yet, all of the notes that I wrote in using an Apple Pencil are gone when I go to re-open the PowerPoint.

Any ideas what could be causing this, or possible steps to take in order to remedy it? Really appreciate your help, because losing my notes from lectures in nursing school makes it pretty difficult to do well. Thank you