How to store u-blox coordinates (lat, lng) values in doubles? [TinyGps++]
You forgot the , 8 from your println that specifies that it should print 8 decimal places. Instead you seem to have added it to the end of an assignment which makes absolutely no sense whatsoever.

double latcord = gps.location.lat();
double lngcord = gps.location.lng();

Serial.println(latcord, 8);
Serial.println(lngcord, 8);