Need guidance on installing a door closer

I've been trying to adjust a Brinks Heavy Duty door closer on my basement door to the garage for weeks. I've exhausted all options provided by their support to adjust this and its still not right.

The problem that I'm having is that when the door is easy to open, it doesn't fully close the door and latch it. When it is strong enough to fully close automatically, the door is really hard to open. My kids have a really hard time opening it. Is there a trick that I'm missing?

We used to have the spring loaded hinge closers and I hated how they slammed the door shut. I love that this closer slowly closes the door quietly, I just wish I could get it adjusted so it is both easy to open and fully closes the door.

Pics of the current install with temporary casing