When I created a whiteboard, I noticed that it was missing the bottom center menu with the different editing features (cursor, pencil, eraser, shape, etc) so I can't really do much with the whiteboard.
1) I created a whiteboard using the option of clicking on the left side bar - advanced tools - create whiteboard. 2) When the whiteboard popped up, I couldn't figure out how to edit it and found your page on "Feature Guide to Whiteboards". 3) I looked at the "How to edit a whiteboard" section and noticed that I didn't have a set of tools a the bottom of the screen which was called the "Bottom Center Menu".
That looks like a plugin/extension might be blocking it - have you tried using another browser and/or the same browser in incognito? Have you tried it on another device?
Closing due to no response for over 20 days - Please feel to respond here :)