When using a custom content type (cct) with Jet Engine, all fields such text meta fields work fine.
Checkbox fields however display fine within WordPress, within the database the import seems to store the values as 1;0;1;1 instead of true;false;true;true, the latter being required by Jet Engine to work properly.
May this be an issue with Import WP or rather some specific database configuration that is required?
Once I open a cct element in WordPress (all checkmarks are correct and remain unchanged for the checkbox item) and save it again, the 1;0;1;1 becomes true;false;true;true, making the entry work again.