Honestly I haven't heard the term PGP here on west coast Canada.
We call it SPD when it's pain in the pubic symphysis and radiating into the groin, hips, legs. Sciatica when it's in the bum cheeks and back of the legs.
PGP is I think more a general term that covers the pubic joint, sciatic joint, or hip joints. So if you had multiple it would be PGP but if it's just the pubic joint it's SPD.