hsaleh and I noticed that WPML sites, such as Belgium or MENA, has the Menu restrictions not working as expected. For example you can add long texts and can Save it without any error message.

Validated against the Brazil dev instance and it's working fine. That's why assume that it's probably related to WPML sites.

How to reproduce it

1. Navigate to any of these mentioned instances and log in to the admin panel.
2. Go to the menus section and edit the Navigation Bar (or the Donate Button) and just type a long text.

Screenshots

Belgium

Brazil