Comparison of long-term Swift X-ray light curves obtained during the 2006 (black) and 2021 (orange) outbursts (Page et al. 2022). The similar behaviour during the early shock phase until ~30 days after t_ref can be seen while the remarkable differences during the SSS- and decline phases after day ~30 are evident. Vertical lines mark the times of deeper Chandra (dotted) and XMM-Newton (solid) observations for the outbursts in 2006 (orange) and 2021 (black) as marked in the upper right legend. In this work, the two XMM-Newton observations taken on days 37.1 and 55.6 are discussed.