Q: Have to open MBP to awake with monitor connected

Hi

I used to be able to click on my bluetooth track pad a couple times and my mid-2015 15" MBP 2.8ghz would awaken from sleep, connected as it is with my BenQ monitor. Now, having done nothing I can think of to cause a change, I have to open the MBP for it to awaken.

Any ideas?

best

elmer