Hi thecoalman, thank you for your help and advice. I already used the tool @ https://httpstatus.io/
with the request headers set to GoogleBot and the response in the html source code is "You are not authorised to read this forum."
Lumpy Burgertushie, thank you for your input. I have checked the forum permissions @ ACP>Permissions>Permission Roles>Forum Roles>Bot Access :-
Post = All set to "No"
Content = All set to "No"
Actions = All set to "No" except "Can Download Files ", "Can see Forum", "Can Print Topics" and "Can Read Forum"
Polls = All set to "No"
Are there any other permissions that I am overlooking, or is there anything else that I should consider looking at ?