On 6th May 2022 at 22:16, during the 3rd milling run to mill off the TRSSV flapper, the circulation pressure started dropping, indicating that we were milling off. The pressure dropped from 4600psi to 3500psi at 3bpm. The operator tried to slack more weight on the mill to start milling again. When this happened, the pressure spiked, indicating that the motor had stalled. The operator Stopped pumping, picked up the coil off the bottom, and tried to mill again. At this time with a pump rate of 2.9 bbl/min and a circulation pressure of 3500 psi, we could not get any pressure increase to indicate any differential pressure across the motor. Tool Specialist contacted the Technical Manager of Through Tubing when there was no progress. multiple attempts were done to check if the motor was working. After two hours, it was decided to Pull out of hole to check the motor. The operator continued to Pull out of hole to the surface when close to surface the operator reduced the speed to three meter per minutes and was trying to tag the stripper, at a depth of 2.25 meters on the injector depth, the reel started turning faster, and the end of the CT pipe came out of the gooseneck and fell to the ground.