Meeting whiteboard function problem

The whiteboard drawing function in the meeting is a bit of a problem. When the organizer has a screen display assigned to another person, the participant in the conference can not use the drawing function in the whiteboard function, even if the organizer and the organizer Turn the assignment to other speakers who also opened the whiteboard function, but also the same can not use the whiteboard function in the drawing function, will pop up the wrong message: "At present can not be drawn at the end of the presentation may allow you to draw, or have not started whiteboard function" On the contrary, when the beginning of the establishment of the meeting, the organizer is the first briefing, the whiteboard function is also open, the meeting of all people can also use the white board all the features. Hope to be able to fix and improve this serious problem as soon as possible, thank you!