I have preload script configured. As of 5.7+ Psalm versions the preloading is forced on analysis start, I've got next errors appeared:

ERROR: UndefinedClass - app/File.php:36:24 - Class, interface or enum named Psl\Type\TypeInterface does not exist (see https://psalm.dev/019)
            $country = Type\non_empty_string()->coerce($country);

By adding return; on top of my preload files, the behavior of Psalm becomes fine (no new issues).