Thank you for the fast response, with the clear explanation, and the recommended solution.
This has fixed the problem completely, and all the links now work.
Will mark as resolved.
Great customer support! Will give the plugin a rating to match.
Edit:
First link should end with parent[]=Australia&parent[]=Victoria&parent[]=Mentone&ged=tree1
The characters ‘[‘ and ‘]’ have been replaced by codes on here too
