Long-term X-ray light curve in the 0.2–2 keV energy band of AT 2019avd up until the first eROSITA observation. Triangles denote 3σ upper limits for ROSAT/PSPC and XMM-Newton/EPIC-pn, whilst the black circle marks the SRG/eROSITA discovery, where AT 2019avd is at least 90 times brighter than the XMM-Newton 3σ upper limit. The error bar on the eROSITA marker encloses the 68% credible region on the observed luminosity.