Chosen Solution
My phone has done this a few times, when it gets low on battery (below 30% or so). It will start to act funky. Symptoms include being slow to respond when I press the lock button, home button, as well as the touch screen being laggy. It hasn’t gotten this bad before though. Now it was having trouble showing me ANY screen when I pressed the home/unlock button even though it was on. When it goes slow, it will open apps about 10-20 seconds after I press them, but then it will not load the apps and then just exit back out. I should mention I’m running iOS 10.0.2 which is a bit outdated. So maybe that’s causing an issue. However, I really don’t want to update it since it will become much slower. Also, this is an intermittent issue. My phone is charged back up again and acts completely fine now. But I still want to solve this issue so it doesn’t happen at all. Thank you!
iOs 12 is actually quite a bit snappier than iOs 10, you can find around the net quite a bit of info, benchmarks, comparative tests and so on. You probably have just a worn out battery that’s not able to supply the necessary peak power. With time things will get worse and the iPhone will start turning off. A battery replacement should be all you need.
