Pages on iPad

I am a writer, and I use my iPad extensively, along with my Windows 10 PC. For years I have effortlessly transferred files back and forth between Microsoft Word on my PC and Pages on my iPad, using the export/import function in Pages and Dropbox as a go-between. Two days ago (Monday evening, 6/7/21, approximately 11:30pm EST in the US) this function stopped working. I can no longer export Pages files to Word, or import Word files to Pages - the app shuts down in the middle of the process. After some experimentation, I discovered I also couldn't export Pages files to epub, though I could to PDF and RTF.

I restarted the Pages app, then I restarted my iPad. Then I deleted the Pages app and reinstalled it. Nothing changed. I have tried the export and import process with existing files and newly created files.

I am running iPadOS version 14.4.2 on an iPad fifth generation, and Pages version 11.1. Everything worked perfectly earlier in the same day.

Interestingly, I tried the same process on my iPhone 8 Plus, running OS 14.6 and Pages 11.0 (which version my iPad was running when the problem started), and everything worked fine.

I have Googled this problem to no avail, so I hope someone out there has some ideas about this.

Thanks!