Non breaking space not working in richtext editor

AEM 6.5

Issue

Using a non breaking space in the RTE editor doesn't behave as expected. 
When replacing an empty with a non breaking space (Alt+255 on Windows, Option+Space on Mac), it works, but when having the cursor on any position and adding a non breaking space, a normal space will be inserted. 

Impact

The operation needs to be done in 2 steps if we want to properly add a non-breaking space. 
Having a regular space instead could lead to a wrong display of the page

Solution

After investigation, it appeared that the behavior is not introduced by AEM, but by the browser itself.
Adding a non-breaking space on a simple contenteditable div outside of AEM has the same behavior