Did Jakab KOHN change his name to KOLOS?

He didnt, and I accept full responsibility for that error.
Only his children changed their surnames.
Here is his death entry confirming that he remained a Kohn.
https://www.familysearch.org/ark:/61903/3:1:S3HY-6963-8XD?i=169&amp...

Please amend the locked profile and add that he was a doctor.
I have also updated the profiles for some immediate relatives, so their locked profiles may also need slight amendments as well.

Thanks Roy

Thanks, I have adjusted his profile

In adding to the family and putting in dates, the family naming pattern became a little more complex.

It would initially seem that the matriarch had two husbands, Izidor Kalos and Izidor Kohn for her children had either Kohn or Kalos as their surnames.
However, her daughter Roza married twice (her birth date confirms this) but on one marriage she gave Izidor Kolos as her father and on the other he was Izidor Kohn. I therefore have to assume that Izidor used both surnames even though there seems to be no official document to support a legal change.

Under the circumstances (once again "It would seem") their children and grandchildren were also known by both surnames, although in this case we do have some documentary evidence that a number of children officially opted to be called Kalos.

(So I wasn't really wrong after all)

Roy