Hi steveu30305817, ericas63164800,
Sorry for the problem that you've experienced with Combine Files.
Would you please submit a bug report and describe the steps to reproduce the problem?
Adobe Acrobat for iPhone and iPad - Feature Request/Bug Report Form
Additionally, a screen recording would be very helpful.
How to record the screen on your iPhone, iPad, or iPod touch - Apple Support
Unfortunately, the Adobe user forums and the online bug report form do not accept attachments.
Once we receive your bug report, we will contact you directly and privately vial email to diagnose the cause of the problem.
Thank you for your help!