When there are Quartermasters in play and you place Pathfinder on Quartermaster, it does not give you cards when you start the game and play them.
From your description it seems you expect Quartermasters already in play when you place the Pathfinding token on Quartermaster to give you each +1 Card each start of your turn afterwards.
That's not what Pathfinding means. It says that you get +1 Card when you play a Quatermaster (in this scenario). The Quartermasters already in play have been played in the past , before there was the Pathfinding token on the Quatermaster pile. So the old Quatermasters do not profit at all from Pathfinding.
Any new ones you play afterwards will profit from it once, when you play them. When they have their 'put a card on me or take a card from me' ability each turn, they are not played again, so no +1 Card effect from Pathfindig happens.
I also checked with the game, and that's excactly what happens.