Hi, thanks for your feedback.
Are you using bumblebee with nouveau? If yes, this is no longer supported, you should switch to nvidia. If you want to continue using nouveau please switch to PRIME. There is more info on this in the related link on my initial post in this thread.
If this is an issue when using nvidia, then am not sure why this is not working, since we already include the patch that is supposed to fix this. So we should further investigate.
Btw, if you plan to continue using testing, please consider adding yourself to our testers group.