Dimmodule vm131

I purchased 4 modules vm131 in order to dim 4 circuits of lights, i have 4 push-buttoms to command the modules using 5 wires so there is 1 wire used as common wire.
When i install 1 module it works but the moment i install the second one , nothing works;

What do i do wrong ?

I am not from Velleman or qualified electrician.

5 wires, one common? surely you should wire on module and one button/switch to each circuit.

The button i presume should be mains rated (i.e. 230-250v) and the load shall not exceed 300w for each module used.

So if you have 6 60w bulbs on a single transformer conencted to this module this is going to be a problem.

For best results, don’t use a common wire.