Hi, @Antony_RObinson. Would you please confirm which chat bot provided the IP address 99.83.190.102? I ask because that is not a correct IP address for Netlify.
Other have reported that this is information ChatGTP is providing. Is that where you were told that 99.83.190.102 was the IP address to use?
Please delete the A record for 99.83.190.102. That should resolve the issue but if not, please let us know with a reply here.