I have exactly the same issue. Server requirements are met and it only happens when I activate the XStore theme. When I remove the theme WordPress functions as expected.
From Apache.log I get the following error:
The process has forked and you cannot use this CoreFoundation functionality safely. You MUST exec().
Break on __THE_PROCESS_HAS_FORKED_AND_YOU_CANNOT_USE_THIS_COREFOUNDATION_FUNCTIONALITY___YOU_MUST_EXEC__() to debug.
I can not provide URL and credentials to the site, as I am creating the store on my local machine (Apple M1) with Mamp Pro and the installation is ONLY the latest WordPress. Nothing else has been installed.