Hello JohnBomb,
Do you see the error in the Designer? I wonder if this is similar to this forum post - Valid Certificate Path Problem
Where they were able to add the certificate to the Vision Clients in the .ignition/clientlauncher-data/certificates directory to authenticate there.
I suggest opening a Support to help troubleshoot this issue if it is possible or not. Please contact us here! We would like to review your Certificate and see what else we find in the logs
https://inductiveautomation.com/support/home/