Use-case:

• go on a sales demo cloud instance back-office with FF
• create a new article object
• add a table in the 'intro' or 'body' attributes
• try to customise the styles
  Result: none of the items in the list are clickable. If you try seevral times, sometimes the contextual menu disapears.

N.B. on Chrome the dropdown list items are clickable, but I had non-reproducable errors (the contextual menu disapears once, et another time the preview generated an XML validation error)