“Menu Position After” option for Custom Post Type does not work

Hi, I found an unintended behavior of the “Menu Position After” option for Custom Post Type (CPT) module (Metabox AIO). When a user has multiple CPTs, one might want to reorder the position of each CPT menu on the admin sidebar for an easier access (e.g., Event CPT after Posts, Book CPT after Event CPT, Chapter CPT after Book CPT). However, when I try to reorder the CPTs, they do not follow the order that I apply.
Sometimes, after I click “Update” button for a CPT, the selected “Menu Position After” option (another CPT or existing top-level menu) changes to the CPT itself (e.g., Event CPT is selected for Book CPT, but the option “Menu Position After” changes immediately to Book CPT, making the reordering process get confused because Book CPT is set to appear after itself.).
In other times, when I select Event CPT for Book CPT (Book after Event), and Book CPT for Chapter CPT (Chapter after Book), the order of Event CPT, Book CPT, and Chapter CPT keeps changing every time I click the “Update” button for a CPT, and do not follow the order I set for each CPT.