My recently purchased PG 251 eccentric lever doesn't always shift from locked to free without making a stop at about the middle. I have to manually pull it all the way back to get "free". The spring is properly greased. So, lubrication isn't the issue. I suspect the spring is the culprit here. But, it looks OK. And, it doesn't happen all the time. A real head scratcher for me.
It's quite possible that the eccentric jack and the pinion yoke or the eccentric jack and eccentric are binding. If you open up the reel and take off the eccentric jack, and the lever shifts smoothly, then I believe it's one of the two.