  NGC300 ULX1 is an ultra-luminous X-ray pulsar, showing an unprecedented spin
evolution, from about 126 s to less than 20 s in only 4 years, consistent with
steady mass accretion rate. Following its discovery we have been monitoring the
system with Swift/XRT and NICER to further study its properties. We found that
even though the observed flux of the system dropped by a factor of $\gtrsim$20,
the spin-up rate remained almost constant. A possible explanation is that the
decrease in the observed flux is a result of increased absorption of obscuring
material due to outflows or a precessing accretion disk.
