Issues with delphes_card_ATLAS_PileUp.tcl

I am generating samples using Madgraph+Phythia+Delphes and I am using the delphes cards that come with the Delphes instalation.

When I used the "delphes_card_ATLAS_PileUp.tcl", I have a strange peak of events for photons with eta = -2 and E ~= 40 GeV.

If I use the "delphes_card_ATLAS.tcl" instead (without PileUp) the problem is not present.

This problem is common in diferent decays and it is more noticible for samples that don't have a photon in the main decay, for example: "generate p p > t t~ > w+ w- b b~ , (w+ > vl l+) , (w- > j j )" ,

I can't add a image to explain better, but for this mentioned sample I end with 542 photons, with etas distributed uniformly between -2.5 and 2.5; all bins have 10 or less events, except for eta = -2, where I have 80+ events.

I can't find a reason for this peak, it only happens for the photons.

I am using the following versions:
Madgraph-3.3.1
Delphes-3.5.0

Has anyone had a similar problem/know what may be happening here?
Thank you in advance!