Running a Sirio P5000 magnet mount. SWR tunes to 1.25:1 on 1-40. It’s very broadbanded across 40 channels. This is running through an amp. When the amp is switched on the swr rises to about 2.5:1-3.0:1 and causes the radio to go into high swr shut off. I just replaced the mag mount base with a new Sirio magnet. It has RG58u coax which I think is not very good and my 18” jumper is tramflex rg8x which I think is much better. I’m thinking maybe I should just change everything out to a so239 stud mount with a good chassis ground and good coax. So I guess my question is, could the capacitor grounding of the magnet mount be causing the amp to see it as a poor ground? Any input is appreciated.