I just switched from EK to Slingshot. Slingshot sent me an email saying my connection was up and running, but I didn't get any notifications from Enable like I usually do when switching ISPs. So, I called Enable and they told me it's because they were actually the same company. That means I can use the same ONT port and third party modem settings, with no downtime, making the switch super seamless!
BTW, $57.95/month for Fibre 300 is the best deal I could find for my area right now.
I don't think EK and slingshot are in bed? But Vocus is the background wholesale fibre provider for them both, and Orcon.
That's probably why you experienced what you did.