FaceTime calls ring iPhone but not iPad
I prefer to make/take FaceTime video calls on iPad rather than iPhone because the screen is larger. Sometimes when a call comes in, both devices ring and I can take the call on the iPad. But other times only my iPhone rings. How can I make the iPad receive incoming FaceTime calls reliably? Does the iPhone take precedence somehow? I have no problems making FaceTime calls on either device.
Specs: iPad (9th gen.) OS 15.2; iPhone Xs OS 15.3.1.
iPad, iPadOS 15