OK I’ve taken another look at the algorithm I was using to choose resolution and made improvements.
This is deployed to the TC and the Plugin.
NB the new resolution scale is 0 - 6 with 0 being the original image, 1 being next highest resolution and 6 being the very lowest.
Please update your plugin/TC and let me know if this resolves the behaviour.
(David I think this is the problem you are seeing, but I could be wrong).