I have a website hosted in IONOS and until now I was using Cloudflare’s free SSL with a flexible encryption mode.
Over the last couple of weeks we have notice that sometimes some people get a NET::ERR_CERT_AUTHORITY_INVALID error, which is either device or browser specific.
I have looked into the forum for answers on how to proceed and seem a bit confused. I can set up a IONOS SSL certificate but that requires that the DNS are within IONOS, so seems uncompatible.
Any thoughts on why we are getting this issue now and how to go about it?
That means you have no encryption in the first place and an insecure site, I am afraid.
The other issue will be the Google proxy certificate, which is addressed in the other thread.
However, the proxy certificate does not really matter as long as you have no encryption in the first place. You need to talk to your host and get this fixed first. If they refuse to issue a certificate, you can try a Cloudflare Origin certificate or maybe switch host altogether.