Almost finished with migrating from a SmartThings v1 to a v2 hub. Only device that’s given me problems is one of my three gen 1 Hue color bulbs. I’ve reset it using a Lutron Connected Bulb remote, re-paired it to my old v1 hub, added it back to the Hue Bridge, stolen and reset it with the Lutron remote and any other trick I could find reading the support forum. What seems to happening is the v2 hub sees the bulb during pairing but it doesn’t create a visible Thing that I can then edit in the IDE. I see zbjoin, Device Created, and Thing Added events in the log for the hub (attached), but no Thing ever appears.
Thinking there was chance that a hidden device was being created in the background that could be made visible, I contacted support. Support helpfully let me know that I needed to use the Hue Bridge–which obviously isn’t true since I had all three bulbs directly connected to my v1 Hub and the other two are working fine on the v2.