Welcome @SeerSnively
Yes, that URL should be much longer. You should see 3 sequences separated by a period (xxx.xxx.xxx). I am not a Fortigate expert but is there a more detailed log that would show the full length of the error you were sent?
I see current certs for your apex domain and some subdomains (www, gateway, remote, ...). But, I didn't see any certs issued for secure.hafoundation.org in the past 6 months. Are you trying to resume using that domain name? If you don't need that name just changing your Fortigate to stop requesting a cert for that name would eliminate the error for it. You might see the message repeat for other "dormant" (zombie) domains. Repeat this for any others that show.