  A leptophobic $Z^\prime$ that does not couple with the Standard Model leptons
can evade the stringent bounds from the dilepton-resonance searches. In our
earlier paper [T. Arun et al., Search for the $Z'$ boson decaying to a
right-handed neutrino pair in leptophobic $U(1)$ models, Phys. Rev. D, 106
(2022) 095035; arXiv:2204.02949], we presented two gauge anomaly-free $U(1)$
models -- one based on the Green-Schwarz (GS) anomaly cancellation mechanism,
and the other on a grand unified theory (GUT) framework with gauge kinetic
mixing -- where a heavy leptophobic $Z'$ is present along with right-handed
neutrinos ($N_R$). We pointed out the interesting possibility of a correlated
search for $Z'$ and $N_R$ at the LHC through the $pp\to Z'\to N_R N_R$ channel.
This channel can probe a part of the $Z'$ parameter space beyond the reach of
the standard dijet resonance searches. In this follow-up paper, we analyse the
challenging monolepton final state arising from the decays of the $N_R$ pair
with Deep Learning. We present the high-luminosity LHC discovery reaches for
six different GUT embeddings and a benchmark point in the GS setup. We also
update our previous estimates in the dilepton channel with Deep Learning. We
identify parameter regions that can be probed with the proposed channel but
will remain inaccessible to dijet searches at the HL-LHC.
