Wiimote connector slot doesn't work.

I've bought two new nunchucks that came today, which are OEM. I've previously had some third-party nunchucks that have been having issues with disconnecting randomly on my white normal Wiimote and my black Motion Plus (both OEM), so because of that, I figured they were the nunchucks themselves.

Both new nunchucks worked great on my white Wiimote, no more issues. But my Motion Plus isn't responding to either.

Is there any way I could repair it? Or clean it even without ruining the port further?

Thanks.