text: i suppose since they asked the government to change the official name they refer to it as propan and keep the name kalamaki to refer only to the beach nearby. but tbh i am not from there and i don't know.
  
  as far as my research went, in the site linked below it is mentioned: "το [...] Καλαμάκι –ή Πρόπαν, όπως το λένε οι ντόπιοι– [...]" which suggests that inhabitants actually call it Propan.
  
  https://www.translatum.gr/forum/index.php?topic=396348.0