If I leave laptop unattended screen goes black and won't respond until it's turned off and then on

My HP Envy 360 is about 2 years old and when I'm using it everything works great. It never overheats and the fan will come on and off when it needs to and it never just sits there running at full blast. If I don't use my laptop for 30 min to an hour, sometimes when I come back to it, the screen will be black but I'll hear the fan running and none of the keys or mouse will wake it up and I'll have to turn it off before I can turn it back on and then it'll start up fine. This has been happening for a few months now, and up until now, if I remember to manually put it to sleep this wouldn't happen, however now even if I do put it to sleep, sometimes when I come back to it hours latter the fan will be running and the screen will be black and I'll have to turn it of before I can turn it on an use it. Things I have done so far include opening the back cover and cleaning the dust with air (it was spotless clean and there was nothing to really clean). I tested the fan and it spun effortlessly. I also updated the Bios on the HP website. I also ran the HP PC Hardware Diagnostic Tools and every test came back saying everything was working fine. My current OS is Win 10 1909.