I have persevered and finally jumped through enough hoops for the techs at my Linux server provider service to take the 403 FORBIDDEN! errors as their responsibility. This morning, after doing some tests yesterday, they wrote back and said that the problems are being caused by an Apache "mod_security" script that they installed a while back for everyone on the shared Linux system. They offered to disable it for me and I said YES. We have a "safe space" closed community here and the restrictions were causing some of us (and me for sure) hell!! I don't know when they will get back to say they shut that thing down but at least there is hope.
Merry Christmas everyone!