I’ve had similar experiences with the “Jew down” expression, Doug. I learned as a child not to use it, mainly because one of my father’s best friends and role models was Jewish. So, as a family we were sensitive to antisemitism.
However, I continued using “to gyp” for “to cheat” well into my adulthood, having no clue that it was a slur against Romany gypsies.
It is funny how strongly people get invested in their traditional vocabularies. I have also experienced people being very emotional and resisting change even when the word origins are pointed out to them.