I recently had a walking foot on a relatively new Babylock
machine stick after using it a few hours. The dealer suggested a drop of oil, which I tried & it only worked for a few minutes.
Since it was still under warranty, I took the walking foot in, he showed me how it was sticking & handed me a new one.
He said sometimes they are faulty & stick.
So if yours is new, I would see if it could be replaced if oiling does not fix it.