The grille brand and model # doesn't show up on Google. Perhaps the grille is some offshore substandard thing??
As stated, with the right connector, it will click in place, but you should pull back the outer ring (if that's what it's called) to allow the connector to go in. Just like fittings on an air compressor.
You may need to buy a complete hose and replace the one on the grille. But then, shouldn't the dealer be responsible for making this work right?
Gil & Deb & Dougal the Springer Spaniel