  PSR B1259-63 is a gamma-ray binary system hosting a radio pulsar orbiting
around a O9.5Ve star, LS 2883, with a period of ~3.4 years. The interaction of
the pulsar wind with the LS 2883 outflow leads to unpulsed broadband emission
in the radio, X-ray, GeV, and TeV domains. One of the most unusual features of
the system is an outburst at GeV energies around the periastron, during which
the energy release substantially exceeds the spin down luminosity under the
assumption of the isotropic energy release. In this paper, we present the first
results of a recent multi-wavelength campaign (radio, optical, and X-ray bands)
accompanied by the analysis of publicly available GeV Fermi/LAT data. The
campaign covered a period of more than 100 days around the 2021 periastron and
revealed substantial differences from previously observed passages. We report a
major delay of the GeV flare, weaker X-ray flux during the peaks, which are
typically attributed to the times when the pulsar crosses the disk, and the
appearance of a third X-ray peak never observed before. We argue that these
features are consistent with the emission cone model of Chernyakova et al
(2020) in the case of a sparser and clumpier disk of the Be star.
