Hinges on Buffet Cabinet doors

The hinges are European soft-close type. They are on my Lexington Furniture Ocean Club Sea Glass buffet cabinet. The cabinet is 6 years old, but the doors have rarely been opened. Today, I opened one and immediately the little round plastic piece inserted into the hinge broke, so the door won't stay closed. I then opened another door...and the same thing happened! All total, 3 of these little pieces broke. It is strange because they don't feel dry or brittle. Nevertheless, the doors won't stay closed without them. You can see one pic with the piece in the hinge and one without the piece. The third pic is of the broken pieces.

I've seen similar type hinges online and they are very expensive, so I would prefer to simply replace the little round plastic "cushions" if you can help me locate.

Thank you for any help you can give me.