This happens with all user roles?
Yes this also happens with logged in users and all user roles. Global Site Access is set to Site accessible to Everyone. I’ve tried checking and unchecking ‘Enable the “Content Restriction” settings for post types ‘ with Post and Page (no difference).
Meanwhile I’ve tried with the classic theme, same problem. I’ve also tried the “Display Specific User Profile with a shortcode” with some hardcoded values to test, same problem.
Found the issue. Profile menu must be enabled in the Appearance setting together with the About tab, and access to everyone. Default tab set to ‘About’.