It seems I have the same problem:
FastCGI: server “/var/run/php72-cgi/php-cgi” stderr: PHP message: PHP Fatal error: Uncaught Error: Call to undefined function wppb_check_content_restriction_on_post_id() in /www/wp-content/plugins/profile-builder/features/content-restriction/content-restriction-functions.php:313, referer: https://www.***.nl/leden/
This makes only the posts page unavailable. Single posts or pages still work.
I now downgraded to version 3.0.1 and the problem is gone.
