“Yes, I can print pages from that though I still get the encrypted message if I download and use Acrobat DC (Win 10).” Aah, that suggests that your browser will print anything it is displaying but that Acrobat is honouring the content creator’s wishes. I will try to look into it.
Good to see you have an effective if possibly crude work-around.
Added in edit:
A very quick search on “printing password protected pdf” turned up numerous sites, such as these two. https://passper.imyfone.com/pdf/how-to-print-password-protected-pdf/ & https://www.maketecheasier.com/recover-lost-pdf-passwords-linux/
I can’t vouch for either of them.