Note: To fix the sound problem between rooms the extension must be reset. Uninstalling and re-installing the extension will NOT fix the problem. The good news is that following these reset steps your data will NOT be deleted. However, just to be on the safe side you may want to export your data using the extension tab Courses / Export
I have a YouTube explaining this here: YouTube link
Please following these instructions exactly.
Click the “≡” button in the upper right corner of the Chrome browser window. Select the Exit button. This will close all tabs and windows and end the process.
Windows shortcut Windows keyboard shortcuts Ctrl + Shift + Q or Alt + F4 + Q will also work.
If you still cannot find an Exit option for windows using the above, then you can also try right clicking on the Chrome icon in the taskbar, then select Exit.
You must Quit chrome for Mac or Exit chrome for Windows for this reset to work. Please do not just close the windows because that will NOT reset the extension. You must Quit chrome for the Mac or Exit chrome for Windows. Also uninstalling and reinstalling the extension will not reset the extension.