SWR Meter Help

Hey all...newbie to the forums! I've been searching and searching for hours and can't find a good answer to my question, so my apologies if there is already an answer somewhere. I'm having a problem with my 2 external SWR meters while tuning my personal truck. My father picked up a Pyramid SWR-14 meter years ago and that's what I've always used to tune the CB setups in our fleet (family business). I always just assumed that it was accurate and tuned our radios with it. A few weeks ago I decided to finally install a permanent setup in my personal vehicle (Ram 2500 Cummins). I decided why not grab a new SWR meter so I would remove all doubt when tuning my new setup. I grabbed a RoadPro compact SWR meter at Pilot. I kept changing around my setup...different antenna, spring, no spring, adjust mount, blah, blah. So I was constantly re-tuning. Final setup is a Midland 75-822 radio with the mobile adapter and a 3' Firestik II on driver side stake hole. Now I know a 4' is recommended in that location, but I just don't want a huge antenna all the time and I like the 3' look. I go to tune the antenna the final time in a nice open area and I lose all TX power! No reading on RoadPro meter or on my radio. The radio was working fine all the other times. Return it to store and get a new one which brings me to today...

Go to an open area to tune...this time making my adjustments on the Pyramid SWR-14 as an experiment. Get it to an SWR of 2 on 1 and 40, and a 1.6 on 19. I know this is not anything spectacular, but since I don't want to go to a 4' antenna I figure it's safe. Here's the problem, I hook up the RoadPro (same location, same everything) and am getting an SWR of 3 on Ch.1 and an SWR of 2 on 40.

Obviously something is wrong somewhere, and I don't know how to tell with what. Here's all the differences I noted:

1.Pyramid Meter is solid as a rock no matter how long I TX. RoadPro will often swing around while I'm TXing actually making it hard to get the needle on CAL and will also swing around sometimes when in REF position. Pyramid meter NEVER does this.

2.When testing the power I get a "swing" when whistling on the RoadPro, but I get NO swing at all on the Pyramid SWR meter.

I'm not sure if I fried my transmitter on the last radio because the RoadPro was defective or what's going on, but I'm baffled.

Any insight would be greatly appreciated!!