myqnapcloud url was working. now it doesn't. why?

[unita]

we were using the myqnapcloud url for a couple of years without issue.

now it doesn't work but I changed nothing either on the NAS or on the computers trying to connect.

my home computer is a macbook pro and was connecting fine. now the only way it will connect is if I use a vpn. again, nothing changed in the environment. why did it stop working?

this is driving me crazy as our staff work from home and need remote access to our NAS!

could it be the certificate used by the NAS? on previous sessions with a qnap support tech we walked through the port connections and that is all fine according to the tech.

any advice would be most appreciated.