There are lots of Embraer EMB-175 in the air, e.g., from SkyWest. On my ADSBx feeder map, they are all displayed as type E75L. But on PiAware SkyAware maps, they are either displayed as type E170, such as SKW5998 (A06F5A) or no type code at all, such as SKW5448 (A82AA8). Meanwhile, on linked FlightAware flight site and linked Airframe.org site, they are all displayed as type E75L.
Is this just a case of PiAware database out of date? (I understand that ADSBx feeder map is operated on server side.) Where does type code E170 come from?