BTT is inactive for a couple of seconds after display sleep

I'm using BTT on a Mac Mini, and it's displaying behaviour I haven't seen before. Specifically, when the display is sleeping and I touch the trackpad to wake it up, then go to use an application (typically Chrome), BTT seems to be in a coma for a couple of seconds, so all gestures will do nothing until it wakes up. This is slightly irksome, as the first thing I typically want to do after waking the display up is use my "new tab" gesture in the browser. It's completely unresponsive until the BTT icon appears in the menu bar at top right.

Is this by design? Is it new behaviour? Can I change it?