Hello @Agency,
Thanks for updating the thread.
I installed WPTouch (free version) on a dev server and can replicate the ever loading under Appearance > Customize problem on my end. Further inspecting the source of the problem using Chrome dev tools I see error message that seems to reflect the issue:
Uncaught ReferenceError: WPtouchCustomizer is not defined http://xpro.com/wp-content/plugins/wptouch/themes/bauhaus/bauhaus-customizer.js?ver=2.2.2
Please note that xpro.com is my dev site. Further, I tried loading the Pro Theme Options panel under Pro > Launch > Theme Options and it seems to work without an issue and I don’t see that above error message up there. In that regards I don’t think it’s a Pro Theme issue and the error message seems to indicate the problem lies with WPTouch plugin. I suggest you to get in touch with plugin developer stating about above error message to find out possible solution.
I have also left a message on there live chat regarding the same error message. I will update the ticket in case there is response from WPTouch. https://screencast.com/t/3ERujiwrDcOr
Thanks.