Problems with wifi calling and handoff

I activated wifi calling (ATT) in my iPhone 6 Plus running iOS 9.0.2, and ever since handoff for phone calls has stopped working. Turning off wifi calling restores handoff. With iOS 9, both are supposed to work at the same time (unlike iOS 8). Has anyone else had this problem? Were you able to resolve it?

My Mac is an mid-2012 rMBP running 10.10.5 (I can't upgrade to El Capitan yet due to a software incompatibility.)

Thanks