Hi George,
Welcome to Q&A Forum, this is a great place to get support, answers and tips.
Thank you for posting your query, I'll be more than glad to help you out.
what kind of connections does your mySQL server allow? Afaik, if you deploy a mySQL Flexserver to the public internet there is always some kind of "firewall" involved... does that allow all relevant connections? If you use a private endpoint for the connection then is an "internal" vnet involved, with at least one subnet... maybe there is a Network Security Group attached to, that blocks that traffic.
Have you already tried this guide to troubleshoot connection issues?
Maybe you give it a try, even if it just leads you into the correct direction...
I hope my answer is helpful to you,
Your
Bjoern Peters
If the reply was helpful, please upvote and/or accept it as an answer, as this helps others in the community with similar questions. Thanks!