As i was supposed to do, i got my 4th badge at Pastoria and then followed Galatic Grunt, battle with him and then talk with Cynthia.
The mission was to healthe psyduck blocking the path and then take the old amber to Cynthia mother, it was supposed to be a galatic grunt locking the cave but there isn't and i can't go further, i tried interacting with the paint on the wall in the cave, nothing appened, tried to log out and log in for maybe update the quest but still the same. And i tried go to Hearthome but the gym is still locked.