Okay, it looks like im hit with the x3-expiration (pfSense with ACME/Lets Encrypt, reverse proxy with HAProxy)
For all my devices, computer android ect all works fine and the cert is valid, but not for my wifes iPhone.
I have done a renew of the certificate, and also rebooted both pfSense and the iPhone but still the iPhone is refusing to accept my certificate.
At least in the browser you can bypass it, but here is no way in the app, not even if I remove it with data and reinstall, same result.
I think an iOS update might help, but she wont because it “might be slower”
So, what now? there should be a “use untrusted server anyway” option in the app