Two Motors one PWM help?

[Mark McLeod]

A few things are wrong here.

If all four of these motors are for driving, then you need some consistency.
Either:

1. Change Open 2 Motor to Open 4 Motor in Begin and use 4 PWM outputs
2. Or keep Open 2 Motor and use PWM Y splitters on both sides of your drive train

The immediate things wrong with what you are doing:
PWM 0 and PWM 1 are signals for opposite sides of the drive train. So those are where your two splitters should come from. One splitter for each side.
The Arcade Drive is mixing the joystick x/y to produce the correct PWM0 & 1 outputs. The Dual Motors isn't compatible that that.

Motor Set Output has an incorrect wire.
The one with the red dot needs to be removed.
It looks like you are trying to treat it like Arcade Drive. It isn't.

There are duplicates for Robot Drive Motors, Joystick 1/Axes/Buttons, etc. setting every one of these in two places. Only one will win.