Max character setting not working correctly

Hello! 

I've got a CKE Editor with a character count of 500 characters. Both in the domain model and in in the editor. 

However, when timing it correct, it is possible to submit 501 characters, triggering a "Something went wrong, please contact the administrator" message from Mendix. 

Here's a video showing it happening: https://youtu.be/XHt-zw1bbQM