As I said it works in Chrome, so my best guess is it is something to do with the locale for where the app is looking for the image/Icons to render the page.
I am attaching an image of the forum edit page and you can see there are no buttons for strong, emphasis, etc. But the hover text appears… I can find mention of them in the code (F12), but as I am no longer a coder I cannot work out what to do next. If you give me a better clue as to what to look for, I would be grateful.
Buttons from Chrome
Thanks in advance