Extended Reader Extensions in Adobe Acrobat Reader failing

We have a very old application which creates PDF files to be signed by our users in Adobe Acrobat Reader.  We updated the application on Jan 9, 2023 to utilize the new Adobe CA, and 90% of our customers were able to continue using our application with no issue.  However, we do have some customers who receive the following error when they try to sign a document:

This document enabled extended features in Adobe Acrobat Reader. The document has been changed since it was create and use of extended features is no longer available. Please contact the author for the original version of this document.

We have confirmed the document did not change.  We can take the same document to another PC and sign the file without issue.  Customer's with the issue experience it with all files they attempt to sign from us.  Based primarily off the timing of the issue (it began the day the Root CA expired), it seems clear that this particular issue is related to the CA change in some way.  We have aldready confirmed the users have the Adobe Root CA G2 installed into their trusted certificates. Verified by going to Edit->Preferences->Signatures->Identities & Trusted Certificates.  Then finding the "Adobe Root CA G2" certificate listed in Trusted Certificates.  We also attempted to trust the CA again, but received a message that the CA was already trusted.

I believe this is not an issue with the PDF itself, as the exact same file can be taken to another PC and signed.  Additionally, this isn't affecting all of our users, but it probably does seem to affect a dozen or so seamingly unrelated users.

Has anyone else seen a similar issue since the Adobe Root CA switch?  Or does anyone have any advice about additional places we can check, or need to import the new Adobe Root CA?