Why double tap to wake up screen doesn't work properly on my Lumia 735?

[Windows Central Question]

Sometimes it does work, sometimes doesn't, its very bad. Microsoft HAS to update that very SOOON! Update the touch, double tap, audio and screen (because sometimes my screen flashes! And the audio is lagged!

 

[xandros9]

cant say about those other problems for sure - but make sure the proximity sensor above the screen isn't obstructed because DDTW is disabled when the sensor is blocked, like when its in a pocket.

I also feel that device might not be working right anyway - so I would soft reset, maybe hard/factory reset and even consider taking it to support.