This past fall was my first season with Max, my 11month old pup. I can't tell you how many times I felt the same as you. I captured a couple videos during some of my hunts so I can remember my hunts and watch how Max progresses. A couple things I've noticed:

When I stick close to Max, I tend to be able to see the squirrel more often. One particular time, he was working at a quick jog from about 50 yards to the left of me to about 50 yards to my right and working back and forth, nose to the ground. As he passed to my right for the second time, I noticed a squirrel darting across the ground and right into a hole at the base of a tree that Max had worked a good 2-3times. He didn't see the squirrel but I just stood there and watched, trying to learn how Max worked. He did the exact same thing your pup was doing. He slowly got closer and closer, circling the area that I saw the squirrel come down from. He made a couple soft barks, staring up at a couple trees then slowly narrowed down to 2-3 trees with a nice, steady bark but not too intense like I've seen him get when he sees a squirrel running up the tree or timbering. I know the squirrel wasn't in that tree so I just ignored him and kept watching him. He did, eventually hit that track where the squirrel ran down on the ground and followed it up to the hole at the base of the squirrel tree. He got much more tense, active and then just started treeing the way I know he does when hes ON THE SQUIRREL. The key point for me was that, most of the time, I need to learn about my dog more than he needs to learn about squirrels lol.

Second point from that hunt. A couple hours later, I noticed a squirrel just out on a limb with the wind pushing the skinny limbs all back and forth. He was only about 30 yards up. Max didn't even get interested or act the least bit squirrely. I waited at least ten minutes, throwing sticks every once in awhile but eventually I started shaking that tree and the squirrel started timbering. After about 60 yards through the treetops, Max took off. I started watching the dogs more to see what Max was doing and the last I recall, the squirrel just timbered out of sight and I lost him. When I caught up to Max, he was circling and eventually started treeing a small, dead cedar only about 10 feet tall and completely hollow with no limbs. I thought Max was slick treeing because "there aint no way that squirrel ran down into that cedar". He was treeing really hard and I just took him off and we moved on. Later, when looking at the video I took, the squirrel clearly ran right down the side of a big oak and into that dead cedar; exactly where Max started treeing really hard! When I was chasing after my dogs, I lost track of the squirrel but my video clearly captured it. Point of that one, trust your dog! I've had at least a dozen times where I start to doubt my little Max and then get surprised when a squirrel jumps out, or starts timbering or I notice only a little piece of ear about 60yds up the tree. I've taken my pups on a couple 10+mile hunts and have gone hours between squirrel action and it wears you down to the point that when your pup does tree you start to question and doubt him. I've learned from my first season that I need to learn to always trust Max unless I 100% know he's wrong, and I need to learn how Max hunts and trees as much as he needs to learn how to hunt squirrels.

Stay positive too! I've noticed I tend to doubt Max more when I'm tired and worn out, with little action. When the action is hot, I never even consider doubting him and approach the tree with a "there's a squirrel up there somewhere, I'm gonna find and shoot him" instead of "Why in the hell are you treeing there? There can't possibly be a squirrel up there!"