Sometimes prints will have issues only at a specific height. The symptoms may be poor fill at a specific height, layer shift that always occurs at a certain Z, or something else that seems to consistently occur at a certain height.

When this happens, I start looking at, and around, the lead screws for Z. I look at the motors, the screws themselves, and the bearings. When I inspect the lead screws, I make sure there are no physical issues, such as nicks or dings in the screw itself and that the lead screw isn’t bent in that location.