I encountered something like this at work. It wasn’t pass related, it was just a means of getting people to make text responses. Ampersands were replaced with some gibberish format, which annoyed everyone.
I got some kind of explanation from our tech people, which I understood to mean that ampersand was used to indicate that what followed was live code. Turning the ampersand into gibberish text was a safety measure to stop mischief.
I’ve noticed ampersand replacements in some news feeds too
The problem is that you can’t send from Hide My Email, except in a reply.
I use it a lot but if I think that I’ll need to contact by email by the HME address, I use one of my AppleID aliases.