On my former UM Merlins, SE530x8, and on Tralucent 1Plus2, the recessed sockets are rough too so I think that's quite normal. However all of them I could push the connectors in to almost equal depth.
Is there a guide rail inside the recessed socket? Do the connectors have channel ridges? If so does each connector's channel ridge match the recessed socket's guide rail?
I might be wrong about this, but iirc, I don't think any of the frogbeats have recessed sockets.