Multiple MOSFETs steering from one signal

I’m doing project where injectors are controlled by 12V PWM signal. Signal is coming from PWM generator and controls the mosfets.
The problem is, when only one mosfet is connected to signal it works perfect, but at the monet of connecting another gate to signal line it stops - injector stops working.
Anyone know what is going on?
I’m attaching circuit below

Do you have schematics for the PWM module, the output driver in particular, and input of the IDUINO boards? Hopefully, the IDUINO inputs are 12V tolerant.

If you are going to start a new post with a question that you asked elsewhere it would be courteous to link to the prior post. so members don't waste time repeating advice, questions, etc.

Where is the vcc 5v coming from that is connected to the mosfet boards? Details matter.

Cut the jumper on the PWM board per the mfg instructions so that the output voltage will be 12 volts (same as vin). Then, connect the vcc terminals of the two mosfet boards to 12v instead of 5v. That should properly drive both non-logic level mosfets.

PWM generator board link