I don’t think a dark room will trigger this as it needs to have the proximity sensor obscured as well. Either way, let me know how your testing goes. I’ve ran into this quite a bit where my screen doesn’t light up if I receive a notification when my phone is on the couch and a blanket or pillow is hovering over the very top of the phone or if it’s on the coffee table a piece of paper or something is touching near the front facing camera.I did not know this. Thanks for the information!
I am going to have to test this out as i can't say whether or not this is what is causing my issue. I'll test in a brightly lit place, then a dark room, and see what happens.