Background subtracted pulsed fraction as a function of (measured) energy using (outburst averaged) NICER data (open circles) across the 0.5–10 keV band and NuSTAR data (filled diamonds) across the 3–66 keV range (left). The pulsed fraction clearly increases as a function of energy going from ∼2% near 1 keV to ∼13% at the 34–66 keV band. The time delay (in μs) relative to the NICER 3–4 keV band showing NICER (0.5–10 keV; open circles), NuSTAR (3–66 keV; filled diamonds), Insight-HXMT/ME (6–18 keV; filled circles) and Insight-HXMT/HE (18–130 keV; filled triangles) measurements (right). Events with energies above 4 keV systematically arrive earlier with an increasing trend as a function of energy than those from the reference 3–4 keV band. Also, the same is seen for (NICER) events from the soft band with energies below 3 keV (not properly accessible during the 2011 outburst).