Using Adobe Acrobat 11.0.18 on Windows 10. This is an intermittent problem -- I cannot reproduce on demand.
I created Custom Stamps with my initials and signature. Sometimes after I have added a Stamp to my document and use Preflight / Flatten annotations and form fields, the Stamp will flip (along the horizontal axis) and move several inches up the page. It does not happen often enough for me to figure out if there are "triggers."
Any help in solving this problem will be appreciated.