My wife has an 05 PT Cruiser, Manual Transmission, about 100k miles.

It goes into first and second gear without a problem but once I try to shift into third gear it acts as if the clutch completely disappears or like there is something blocking it from going into gear. Usually I can wiggle the clutch from side to side and eventually get it into third but it takes a lot of effort.

Does anyone know what is going on? or at least can you point me in the right direction?
Thank you!