Hi, sure. I’ll summarize what I’ve read there:
– You can’t open the customizer if you have Adsense on with “Advanced Ads – Ad Manager & AdSense”
– You were working through several console errors
– Your console seems to point to a Jetpack connection error
– Their support sent you here
I doubt that fixing our connection error will solve the customizer problem you’re facing. You could test that by temporarily disabling Jetpack. But, fixing this issue will help Jetpack work better!
I tested your site and found it’s timing out, like the second error message listed here:
https://jetpack.com/support/getting-started-with-jetpack/what-do-these-error-messages-mean/
Most commonly, asking your host to change the PHP_FCGI_CHILDREN setting to 2 will solve this issue.
Once you’ve done that, could you update us here with your result?