Scrolling action make autosave looping endless

Reproduction steps

1. Go to Nuxeo
2. Open a document
3. Go to Annotation tab
4. Create a circle annotation
5. Wait for autosave to be done before doing anything else
6. Create a circle annotation
7. Scroll the page during the autosave => autosave is looping endless, the annotations disappear from left section and the user has to refresh the browser to have Arender working well
    
   Observed results
   5. the new annotation is saved, ** 
   5. Autosave stoped after a few seconds,
   5. the user can continue working on Arender view,
   7. autosave is looping endless,
   7. the annotations disappear from left section
   7. the user has to refresh the browser to have Arender working well
    
   Expected results
   5. the new annotation is saved, ** 
   5. Autosave stoped after a few seconds,
   5. the user can continue working on Arender view,
   7. the new annotation is saved, ** 
   7. Autosave stoped after a few seconds,
   7. the user can continue working on Arender view,
    
   Description
   Arender doesn't handle correctly actions from the user during an autosave, even scrolling.
   The user has to refresh his browser to go back to a normal behavior.
   Version: 4.0.6.NX2.1.

Mostly reproduced with circle, freehand, highlight rectangle