Issue with Files App or Word Doc

I keep encountering this issue even when I used Macbook Pro in the past and now with the Ipad Air 11, where I would be using a pdf doc in the Files app and suddenly it just reloads to the first page and deletes everything I’ve worked on below. It also occurs in the Microsoft Word app. I am not sure if this is an issue with my iCloud Drive.. It gets so frustrating as I would be doing school notes and suddenly it all just disappears and I can’t get it back. May I know what I can do or is there nothing to stop this issue? Thanks.