What does the "Ias" attribute reads for this device?
If you're pairing against a C-8, you can try the double-luck voodoo trick:
If that fails (or does not apply), try to power off the hub (Setting -> Shutdown), wait for the red LED on the hub (shutdown complete), remove the USB power cable, wait 30 seconds, re-insert the USB cable and wait until the hub starts up (green LED). This will reset the Zigbee circuit/board inside the hub, maybe it got stuck in a weird state.
If that fails, try to use the "Advanced Zigbee pairing" function from the Zigbee Map app, to make really, really sure that the device is pairing against the Hubitat hub, and not one of the close by repeaters.
It's also possible you got a bad unit, and can replace it in an IKEA store (if you still have the receipt).
Hope this helps!
