Pro has 3 already minified scripts loaded in the frontend and they are:
Some of the code in those files are jQuery dependent so jQuery is required to be loaded in the
<head> before the
There’s a chance that the JS code will break due to minification of an already minified file. The said files should also be loaded in same area and in order therefore it’s best that you exclude those files. You should contact the optimization plugin support to learn how to exclude all resources of a theme or plugin.
This was also mentioned in our Performance Guide at https://theme.co/apex/forum/t/customizations-performance/210
If you wish to continue minifying and concatenating the theme scripts, you will need to consult with a third party developer as this is considered custom development as website optimization work is quite involved.
Hope that gives you enough information to continue with optimizing your site.