Hello @Pentagon2442, welcome to the community and to OpenZiti!
That is a very interesting issue you have there! I would not expect a 400 to come back from the enrollment.
Can you detail the exact steps you've followed so that I can try to reproduce what you're seeing? I have very recently done exactly this setup, but used docker instead of CentOS 7 VMs. Maybe that thread would help you? Accessing remotely (Docker) - #6 by TheLumberjack
It's certainly easier if you let the quicsktart generate the PKI for you. It's a very delicate thing and exceptionally easy to get wrong. We recently added this to try to explain what a quickstart does and how the PKI is structured etc Quickstart Walkthrough | OpenZiti. Maybe that will help too.
I'll be happy to help you get your setup rocking. Take a look at those links first, show me the exact sets of commands you've run and I'm sure we'll get you rocking in no time.