Hello ponton -
Apologies for any difficulty with the new templates and the template selector. We are aware that the default selection for images in the selector is 5 and that it currently requires that you select the number of images you wish to use in order for any number of images over 5 to post properly. However, we are, in the very near future, releasing a change to that selector to avoid this issue as at this time there is no way to set a different default number of images.
I'll update this thread as soon as there is more information available regarding this issue.