Thanks, but as I said we have tried in postman, both with the template and manually. Still the same error, still nothing in the audit log so no way that we can see to determine what the issue is.

what does the environment look like

message has been deleted

does the account id exactly match the value from SOAP Web Services Preferences

Yes it does. (Copy/Paste). I'm sure it is possible we could have made an error somewhere in the dozen or more different ways we have tried to do this preventing it connecting, but I just don't understand if I have that Account ID right why we don't at least see the failed attempts in the Audit log, especially when the extra details from the failed connection tells us to check there.

does the company url match the suitetalk web services url from company information

Yes it does. I copied and pasted from that location too.