Air conditioner issue FYI (fix inside)

So for the last couple of weeks I've noticed my inside unit seems to be short cycling. I came home 1 day and found that the inside unit had a light layer of frost on the back of the evaporator coil and some on some of the hard lines.So I called out the AC guy cause the unit is only a year old inside and out, he came out checks the freon, all pressures and Temps were good. Inside coils clean and drains free and clear. Cannot duplicate the problem.

So another week goes by and I happen to be walking past the unit return air grill and I hear what only can be described as like a steam locomotive idling at the station I like this shhhhhhhh sound coming from the inside unit behind the filter. Fast forward to today I have a scheduled yearly maintenance check so I told him it's still acting funky and I played him the sound I heard from the inside unit because I recorded it. So this time with his helper he had shut off the inside unit and we waited and it made the noise so he went outside and check the compressor and it was still running.

Come to find out it is the contactor on the outside unit staying closed when it should be open. It was allowing the outside unit to continue to run which I believe caused the icing issue and the sound was it actually trying to circulate freon on without the inside unit running. The fact that it took multiple service calls to catch it is because the contactor was intermittently staying closed. All good now.