Okay guys, the few that mentioned the gunk inside the well that the 510 wheel spins on got me thinking... that can't be good for conductivity! It might very well be the reason why the Ohm readings are off. I posted this in another forum so sorry for any redundancy...
So my 2.1 ohm head has been the one giving me most problems. Even on VV, I would still check my ohms just to see how often it jumps around. It jumped a lot.
Now, I'm going to tell you what I did because I don't know exactly what fixed it (so far, more than 10 chain vapes in and the ohm stayed dead on 2.2, which is the first time it didn't jump with that many fires).
1) I took my atty out. Grabbed an alcohol prep pad (70% iso, but if you have 99% around, use that instead with a paper towel or something or just dip a prep pad in it) and a toothpick. All this talk about machine grease inside the 510 connection got me thinking... that can't be good for conductivity. There are two slits on that wheel. If you look inside them, you can see the well that the wheel spins around on. Well, that well has some gunk. I put the prep pad in the connect, then used the toothpick to get the pad inside that well. Then I spun the wheel back and forth with the toothpick pushed up against the well to catch any gunk. I did this around the whole well. You can also get the pad and toothpick on the outer edge of that well. What came up was brown gunk (might be from some juice leaking as well).
2) I spun the wheel counter-clockwise for a while. Maybe about 20 rotations.
That's it! So far this has done the trick! So I'm really hoping it was the gunk in there that was causing this issue!