Hi again, Louie here. Sorry you had to wait awhile but I’ll do my best to help.Initially and even if "...a protected PDF...", would it still allow to be printed?
Can you try print to file ? ...not actually sending the document to a real printer but to an Adobe PDF Converter?
The idea is to print (actually re-save) the "...protected PDF..." into another / same pdf file (slightly different file name) but less the locks/protections.
Then this identical file but with a different file name can now be edited and re-saved.