Oyster Clasp hinge problem

[JeffR50]

Hello, Newby here so please forgive me if this question may have come up before.
I finally got my no-date Sub (ref: 124060) this week (after nearly a 3 year wait). The hinge on the foldover clasp is extremely tight and it takes a lot of force to open and close it to get it over my wrist. When I first got the watch, the hinge moved freely as it should but after a few days, it became stiffer and stiffer to move. Anyone else have this problem? If so, does it just need to be lubed or is it defective perhaps? Thank you.