I had the same problem with mine.
Maybe is noise, Have you conected the PC and electronics from the same line of the plasma? If so the HF will stop the plasma from the PC. Get a long extension and conect the PC and electronics from other line. Also gorund the plasma alone (1.20mts rod ),other for the table and the ground for the E. and PC, from the building should not have interference or better have another copper rod.
TherLuismal dynamics starts different from other plasmas , the first fire takes longer time , then you have to put that delay (or preheat) time in the cam program.