Looking for part for drawer slide

I'm not sure if this is the right section for this post so please direct me if you know of a better place. My kitchen cabinets use all DTC under-mount drawer slides and hinges. Its a Chinese company and the drawer slides have been working very well for the past five years until just recently. It seems the "catch" on three drawer slides have broken. Cheap plastic. It's the blue piece in the center of the image below. Naturally, I'm having a hard time finding a suitable replacement piece. I can replace the entire drawer slide with Blum brand slides, but with three drawers already needing replacement and more to come in the foreseeable future, it seems like a waste of money to replace otherwise fine slides just because of a small plastic part. Please take a look at the picture and see if anyone can guide me in the right direction. Thank You