First of all, thanks for posting the vids! Love seeing progress!
Velvets brought up the exact FIRST thing I noticed in both videos, in that he's bent to the outside consistently in both videos. Bend takes a long time to understand and to grasp, but he will never be fully through/over his back until you get him going forward and bent in the right direction. I also agree that there is way too much rein there. I had the same problem when I first started - this is like a "false contact", where it looks like the horse is working on the bit/in the contact but isn't really.
Suffice to say its coming along. He is not going to "focus by himself". This is something you have to help him through by showing him what's acceptable and what's not in an appropriate way. Next time he goes to bend to the outside because he's used to it now, continue with a forward trot, and literally bend his neck/body around a 10-15 meter circle until you feel his head actually give/drop. You need to be able to see the corner of his inside eye for you to know that he is bent the right way (among other things). The goal is to loosen up his jaw, get him chewing on the bit, and stop bracing against the inside rein.
Persistence is key. Can't wait to see more.