A spectrum has now confirmed it an “ordinary star” so the source of the variability is unclear.
https://www.astronomerstelegram.org/?read=14593
A series of spectra covering a period of variability could be interesting. (The clouds rolled less than a minute after I finally got the star on the slit of the ALPY600 when it finally cleared the rooftop at 16 deg altitude). Although extremely noisy, the spectrum is also consistent with the “normal star” description)
Cheers
Robin