Hi Brook,
I have solved the illusive theme issue. By updated the theme to the latest version it seemed to solve the Featured Image problem, I also checked the code that I had originally place to add theme support and it was no longer needed.
For anyone else out there I noticed that within the package are updated plugins that also need to be installed one of which is for woocommerce, may be a coincident but once everything was up to date it all worked, so I’m happy.
Thank you for being available and have a great day
Olaf