Note that URLs are only technically valid if they have a protocol (in this case https). We do try and coerce this out as a valid URL, but we will assume "http" and in the case of Google, this will redirect to the "https" version of their page. If a redirect happens and you're running the latest version of XF, then for security reasons our HTTP client won't follow this and therefore won't return the correct title.
So, try the link as exactly as I wrote it above and let us know if that works.
For example if the URL you are posting does any sort of redirect, then we won't follow that redirect.
However, it could also be down to domain name resolution or a firewall issue on the internal network your server is connected to. Your host may be better placed to advise you and support you with this.
I do this question aside, because now the problem may be due to the fact that the test forum is on temporary hosting. When I take the final forum on Xeno, and if the problem remains, then I will. Thanks for the help.