Windows 10 won't go to sleep - black screen

Whenever I close my laptop lid to put Windows 10 to sleep, it won't turn off properly - the computer continues to run, as indicated by the power button and the three lights on the side of the laptop, but I'm stuck on a black screen and the only way to get out of it is holding the power button and turning it off completely. Anyway to fix this?

I've made three threads for similar issues in the last few days and absolutely none of them have received replies