How can you have over a day of battery life with screen time yet it is claiming it has 50% screen time out of your 1 day and 7hrs of usage. Looks like you connected it to your computer every now and then, which charged your phone ever so slightly without resetting the counter. Unless it really isn't able to count
Something is off I think.
I would NEVER play games with battery lies, NEVER. That's not the way I roll. I am very honest on battery life on my phone, most have sucked usually.
I did NOT plug my phone in at all that time for 31 hours.