Why is FaceTime Handoff not working from Mac to iPhone?

handoff is not working from mac to phone for any app (sometimes), but works from phone to Mac.

Specially FaceTime - when I call from iPhone, the switch on Mac shows 'facetime on iPhone' now, whereas previously it would show 'FaceTime "on my device's name"'. It's annoying because I use handoff for FaceTime the most.

this is really frustrating as handoff randomly stops working a lot of times, and I have already restarted my devices and signed in and out, and my devices are up to date.

TLDR: the issue is that handoff works, but stops working randomly as well.

[Re-Titled By Moderator]