What are you Rewarding?
What are you getting Repeated?

What is getting rewarded is getting repeated.

I found this quote somewhere and I don't know who to give credit to.

What is a reward? a thing given in recognition of one's service, effort, or achievement.

What is being repeated in your class or professional learning?

Students not completing task?

Teachers talking during your PL?

Students not engaged in your lesson?

I would look at your reward.  

I have a student that will gladly take a zero so he doesn't have to complete the assignment.  This is  negative reward but a Reward.  Negative attention is also attention and some students will take attention anyway they can get it.

Teachers during PL will not participate or are engaged during PL. Check what type of Reward they are being given during the PL.  Are they getting a reward?  Are they engaged?