I checked your domain.
We got an error from our cert authority:
Failed to create Order: 429 urn:ietf:params:acme:error:rateLimited: Error creating new order :: too many certificates (5) already issued for this exact set of domains in the last 168 hours
In this case, the easiest way is to create a new subdomain for your sGTM.
I think this is connected to your open ticket in our help desk.
I faced the same NET::ERR_CERT_AUTHORITY_INVALID error even though my domain showed as ready. The problem was that Traefik was still serving its default self-signed certificate instead of a valid one. What worked for me was checking that the A record had fully propagated, confirming the CAA entry allowed trusted authorities, and updating Traefik to use the correct certificate resolver. After a restart, the proper SSL certificate was issued and served without errors. Hope it helps!