Same thing happened on my brand new Squier Classic Vibe 70s Thinline I bought last December. Only one tuner, but it was a mofo. I tried a few things before resorting to replacement, including lubrication, using a string winder to run a couple hundred revolutions in each direction. No love.
I replaced all of them with a new set of Fender/Gotoh vintage tuners I had on hand for a future build. Had to replace the tuner bushings as well, as the stock bushings were to small for the new tuner shafts. Not a difficult job, and the new tuners work like they should. It was a GuitarCenter online purchase so I just took care of it myself. GuitarCenter does not have a tech I would trust to do this right, even though its pretty simple.