Jossi,

Have you seen Dr. Dan Hirshberg's website?  https://www.ics.uci.edu/~dan/genealogy/

Dan has recreated most of the Jewish citizenry of Krakow.  I do not know if this data is also in JewishGen, but if it is, I don't think it includes Dan's search engine.  One of the features of his free and searchable database is the family trees of hundreds of Jewish surnames in Krakow.  I checked yours.  It is there, in the "Early Family Trees" tab, under the name "Jolas", last updated January 15, 2021.  That tree starts with patriarch Izaak Jolas, 1769-1846.

Good Luck and Happy Hunting.

Ken Domeshek - Houston
(Damesek, Kartorzynski, Braverman, Sinienski, Simonovitz)