Debugging new model from feynrules

I implemented a Toy model made of one broken U(1) gauge group with vector boson V, with 1 fermion F and 1 complex scalar S that acts as higgs + goldstone to give mass to the U(1). Making the usual checks with feynrules gives no error (hermicity, mass diagonalization).
But if I import the model in madgraph some cheks fail

In particolar:

All All > All All is ok

All > All All gives error and don't finish the check:
RAMBOError : Not enough energy in this case
Please report this bug on https://bugs.launchpad.net/madgraph5
More information is found in 'MG5_debug'.
Please attach this file to your report.

All All > All can finish the check but gives many failures for the Lorentz invariance test. More specifically, I checked that for every selection (X,Y,Z) such that X Y > Z gives failure, X > Y Z gives error

Moreover, in the final summary of the check, the MIN elements of the failed processes have a ratio of
6 if the initial state contains a spin 1/2 fermion and a spin1 particle
9 if the initial state contains 2 spin 1 particles
3 if the initial stats contains 1 spin 0 particle and 1 spin 1 particle
2 if the initial state contains 1 spin 0 particle and 1 spin 1/2 particle

And that the processes containing only scalars are all passing the test.

From this, looks like a spin average problem...plus the fact that it does not discard automatically processes like V > V S that cannot happen as both S and V are massive