Starting problem?

So I have the truck listed above k1500 5.7 with the Vortec, and when I go to start it for the first time of the day, night etc, engine cranks fine for roughly one second and half and then catches not as in the starter gear catches the flywheel but as if something catches the flywheel and pauses the starter for a second the flywheel turns but it goes slow and give a drained battery sound and you can feel the flywheel almost forcefully turning with friction and it shakes the truck and sounds like bang every time it turns. Now sometimes it won’t do that and crank just fine or after it’s warmed up it will start just fine. Even when it’s acting up on first start it will always crank and start but with some patience. When I first got the truck, the starter would take almost 10-12 seconds to start the truck. It would sound like an old diesel on a winter morning, so I immediately thought the starter was bad but let it live the rest of its life out. So, I came to the conclusion that the starter is bad, my crank is seizing up or there’s an issue with the flywheel. What do you guys think? Anyone ever run into this problem?