Featured page

Hello,
I’ve been using Kale for more than a year, and never had a problem till today. But now I noticed that I cannot get the featured image working for pages. It works for posts, though.
I tried with both the default and the full width templates, with no luck.
I’m using a child theme, and the funny thing is that the development version of the site works perfectly on my local environment (using MAMP). Both installs run on PHP 7.2x and WordPress is updated to 5.0.1 version.
On the online version the page featured image works only if I revert to parent theme (which, by the way, is up-to-date).
Also in both installs something funny is happening with Kirki/Customizer: none of the pages options are available and the corresponding customizer section appears to be broken, both for parent and child theme (see screenshot here).
I checked all the templates and made sure that the parent and child themes files are synced between local and live install… but I’m obviously missing something. Any help would be much appreciated.