not working properly at presentation mode

in a session, I was a host and i tried to allow control to participant.

after click to allow, not changed check mark like image, but participant could control my presentation.

Problem is I can't take back authorize to control. I mean, not possible to cancel to allow control my presentation.

teamviewer version is 14.2.8352. (I checked ver 13. working properly)

I'm not a native. So i'm hard to explain what I want to say. but i think you know what i'm trying to say.