Acrobat DC won't accept the correct PDF password, but Acrobat Reader will

After a six-month wait, I received an email with some PDF files I had requested from the National Personal Records Center. The files are protected with a password that was included in the email. When I try to open any of these PDF files, Acrobat DC tells me it's the incorrect password. YET, Acrobat Reader DC accepts the password. As does Google Chrome. And Safari. I pay Adobe for the convenience of their apps, like being able to remove a password from a PDF. The only way to do this is to open the PDF in Acrobat DC which is the only application that will not open it. I need to share these PDF files with the VA to help my family and have no way to do it. (Copies, screenshots, etc., will not work because they don't have the required digital watermark embedded in the original files.) 

I use a MacBook Pro, Apple M1 Max chip, running Monterey v12.5.1. (Yeah, I already talked with Apple and did a screen share with them for 25 minutes. It's not the MacBook.)

Can anyone help? Trying to solve this problem is like having a second job.