Thank you for your reply. I am excited to hear confirmation that Czaja is/can be a Kaschube name (many spellings depeding on the language.
Maybe your family can find out if there are relations to the Czajas who used to live in Schoppa (Szopa), from the same region. Would love to hear back when they return. you can email my direct email if you want:
tmbachmann@yahoo.com