I have a Radiooddity QT 60 connected to a Tram 1498 via 50' of TM LMR 400. I connected it to my Maverick 250, then my LP 100A after the amplifier. The radio sees an SWR over 3.5 with the amp on, but the LP 100A reads 1.4. at the output. Without the amplifier online, the radio and LP 100A see 1.3. If the radiio is seeing an SWR of 3.5, I assume it's not safe to run it. My question, is what are the possible causes?