The link to the slot through Major drill quest (I think) leads back to the old location of the slot page. Either way if you click on the link to go straight to the slot page it gives you a 404 error page.

It does. Unfortunately its been this way since the New Slots page came out much like how the gifting another user link was broken for drills, because updated the gifting page. Actually, its been a while since I have seen gifting ask in Drills 🤔