You might need to add the VI - it's hard to read your wiring.
I do see a potential conflict. You have cases for:
- One greater than another
- Both within 5 of each other
- One less than the other
However, it is possible to be in more than one case simultaneously. If A is 2 greater than B, you'll trigger the first case and the second case. In the first case you set motor values of of .1*, in the second case you set motor values of 0.
The robot will dutifully apply both, so you'll rapidly be switching between some power and no power. This could stop your robot from moving at all.
*On a side note, many robots won't even move unless the motor powers are ~.3 or even .4 depending on robot weight, friction in the drive train, trying to turn, etc. Try ramping up the power temporarily to make sure that isn't the problem.