neither mvp or 134 are mech mods. Do they have adjustable 510 connections? I would never use an RDA on either of those mods, they just don't put out enough power.
The 134 has a self-adjusting spring loaded positive pin. When I was still using clearos, specifically Nautiluses, the spring loaded pin on those tanks were causing so much opposing resistance that it would cause the tank to "pop" out when un-threaded which was slowly but surely damaging the threads, eventually making it impossible to attach most atomizers.
The friction was also causing the pin in my 134 to spin in place. I was getting a lot of connection issues like the one described until the pin twisted so much that it separated from its wire. After re-soldering the connection and buying a
ego-to-ego/510 adapter I got the use of my 134 back, but by then I had already switched to mechs for the increased durability.