Has there been an update on this? I’m having this same problem.
I have two sites with Pro. One of them works fine. My other one, works fine within dashboard, but when I go to “Customize Pro in Theme Options” it asks me to login. When I login again, It brings up a window asking me where I want to go. My other site does not show this window when I click “Customize Pro in Theme Options.” My other site takes me directly to Theme Options.
My site that it’s not working on https://steffenharris.com, shows this window. When I click on any of the options (Headers, Footers, Theme Options, etc) I get a login window again, but the link I clicked never loads. it just keeps asking me to login and then select an option. If I wait a few seconds without doing anything, the login prompt opens up.
Wordpress is 5.2.1
Pro is most recent version
Links in general settings are the same.
No Cache plugin being used