Temporal evolution of the 2023 outburst monitored with NICER. Top panel: the 0.5–10 keV light curve using 10-s bins. The type-I X-ray burst (Fig. 1) was filtered out to perform the timing analysis. Second panel: pulse fractional amplitude. Bottom panel: pulse phase. The orange dotted line represents the data modeling conducted separately for the intervals before and after the phase jump (see Table 2), along with a vertical line indicating the phase jump of ∼–0.25 cycles.