Ralph, I tried

https://www.hebrewsurnames.com/search
https://cemla.com/
https://amia.org.ar/sepelioscomunitarios/busqueda-de-sepulturas/
and could not find any Grodner that arrived or died in Buenos Aires, where the vast majority of Jews live.
Do you have any more information? Is it possible he went to another country?
I also found an interesting site at
https://www.jewishgen.org/Belarus/newsletters/grodno/GrodnoFamily/index.html

Good luck in your search

Angel Kosfiszer
Richardson, Texas