I believe Poppelau in Selesia, is actually Popielow in Slask.
I will check if indeed this town is located in the upper region, which would be closer to the mountain range where usually Lemki people lived. Lygas were Lemki - not Polish and not Ukrainian. Had their own language, culture and a mix of byzantine/orthodox religion.
You may read more about it when searching on google: Lemki.