Car overheating noticed my car was leaking anti-freeze

At the beginning of the year, I noticed my car was leaking anti-freeze. It turned out to be a loose clamp. A couple days later the car started to overheat--turns out the thermostat needed to be replaced. It runs fine at this point

About a month later the car starts to overheat again, this time the radiator cap is replaced. The car runs fine again.

Another month passes, the car starts to overheat again. I take it to the dealer. The coolant is low and there is air in the line and is bled. The car runs fine again.

A couple weeks later, I notice some dried antifreeze on the oil pan. Water pump needs to be replaced.

Now a month later, the car overheats again. I take it back to the dealer again. Air in the lines again.

Continually, the car passes all sorts of pressure and block tests. Coolant looks good. Oil looks good. The dealer is hesitant to say the shop who replaced the radiator cap and the water pump did a shoddy job on pressurizing the system, but also admits there is no evidence of a head gasket problem.

I would welcome any thoughts.