Excel iOS app not autosaving and freezing.

I use excel on an iPad Pro and it now hangs up while closing out more than 50% of the time. If I open the file, make 1 quick edit and close it, it typically works. But if I’ve been in the file for 10 minutes or more and made multiple changes, the autosave doesn’t work, the file hangs up, and I have to hard reboot my iPad to regain use. This has become a big problem in the last month, and even more significantly in the last few days. (My excel & iOS have been kept up to date all the while.)