Hey — not your fault, the mod just doesn't signal this.
The stations are sitting in the hub because the ring starts PAUSED and won't pull from the hub until you switch it on. Easiest way:
Open the status window — the second button on the shortcut bar ("Storage rings"). Your planet should be listed there with a "Resume" button. Click it. That's it — the parked platform's hub will start feeding the ring at one station per second, and you'll see the count climb in that same window.
Make sure the platform is actually parked in that planet's orbit and it's your force. And the rocket-launch part is vanilla: a rocket only flies when something in orbit requests the item, which you already sorted.
Next update I'll make rings auto-activate on first delivery so nobody hits this. Thanks for the kind words!