Smartthings Water Sensors - will pair with old v2 Hub but won't pair with new ST Wifi

I’ve got a bunch of ST Smartsense water leak sensors and they worked fine with my old V2 Hub. However, when I try to add them to the new Wifi hub, they will not pair. I have re-paired with old hub, deleted and tried to re-pair to Wifi hub with no success. I can see the ST Wifi hub led flash from green to red, like its in pairing/discover mode, but device add times out. Any ideas?


Have you done a factory reset on the sensors?