Jet phi distribution modulation (Delphes-3.0.12)

[Simone]

Dear Delphes Team,

I found that the phi distribution of the reco jets (see attachments) present a clear modulation that probably follow the segmentation of the calorimeter cells (72 for |eta|<1.5, 72 for 1.5<|eta|<2.5). Is this a known issue?

Thank you

Notes:
I'm running DelphesPythia8 with pileup, the configuration card is based on the default delphes_CMS_Pileup config file. Since the pt cut on jets is 10GeV, the majority of the jets in the plot come from pileup vertices (anyway the aspect of the distribution is the same for different processes).
The modulation is absent in the distribution of the gen_jets.
The pileup file was generated with Pythia8, it contains 1M of minimum bias events.