iPad OS 17.5.1 Markup bug

I am unable to markup PDFs sent to me by email and reply back to the sender. I can see the PDF, and am able to markup the document, but when I tap done and reply to sender, I get sent back to the inbox, and no reply is created.

It works to save the document to files and attach it manually to a reply, but this is not the expected behaviour. The reply function used to work before the update.

I have tried the obvious fixes -- reboot, backup, restore, but the behaviour persists.

An old post with the same problem is here:

Mail PDF markup reply - Apple Community

But there's no solution given there (or any other reply).

Thanks in advance.