Pythia failed due to no open decay channel for id = -24

Dear Madgraph expert,

I am using PYTHIA to shower a gridpack generated with Madgraph5 in CMS workflow, where the process I have in gridpack proc card is:

generate p p > w+ > w+ h2, h2 > h1 h1
add process p p > w- > w- h2, h2 > h1 h1

which should be a very simple process, and for PYTHIA fragmentation I have set:

processParameters = cms.vstring(
                                    '25:onMode = off',
                                    '25:onIfMatch = 5 -5',
                                    '24:onMode = off',
                                    '24::onIfAny = on',
                                    '-24:onMode = off',
                                    '-24::onIfAny = on'
          ),
where I request the higgs decay to bbar and W+/- decay inclusively.

And in pythia it returns error:
 PYTHIA Error in ResonanceDecays::next: no open decay channel for id = -24
 PYTHIA Abort from Pythia::next: reached end of Les Houches Events File

I am confused, shouldn't -24 be the normal W- boson and dealt by Pythia normally?

Sorry if this question is relevant in the forum, if so please let me know and I can delete it.

Cheers,
Jordan