Long-term evolution of the broad complex parameters. Top panel: evolution of the centroid frequency ν. Bottom panel: evolution of the fractional rms. Cross markers represent the values for the broad feature in Chandra data, while blue circles and orange squares represent the values for the broad feature and the candidate QPO, respectively, in the latest XMM-Newton observations. For Chandra we considered events in the 0.5–10 keV band, while for XMM-Newton events in the 0.3–10 keV band.