That appears to be our same findings & cause. (The openssl command shows it working but that is due to newer openssl libraries I believe and the same reason testing via curl shows everything is ok, our application unfortunately is stuck on a far older Java version which doesn’t support SNI so looking into alternatives to get us back online if the cert cannot be fixed on the companies house side)
Can someone at companies house confirm the findings for the non-SNI certificate? Is this something you can fix or is this no longer being offered?
@MArkWilliams had to add my response here due to a limit of 3 replies per thread !?
We have just checked and we can see our calls are all successful now.
As for using IP addresses we are using the api.companieshouse.gov.uk domain in our requests but I will check if there is something strange somewhere converting that to an IP address.
Thanks for your help getting this resolved.