Hi saeid103,
Thanks for contacting Apple Support Communities!
We understand that FaceTime on your Mac notifies you of a call right after you end a FaceTime call on your iPhone.
Are you able to reproduce the same behavior after you restart both your Mac and iPhone? If you need help to restart your devices, we've included resources below which will show you how to restart:
Shut down or restart your Mac - Apple Support
Restart your iPhone - Apple Support
If you're still experiencing the same behavior after restarting your devices, we'd ask that you create a new user account on your Mac, sign into FaceTime and test a FaceTime call on your iPhone to determine if the same thing happens. This will tell us if this behavior is isolated to one user account or if it's system wide: New user or group setup on Mac - Apple Support
"To add a new user or group, choose Apple menu
> System Settings, click Users & Groups
in the sidebar, then click New Account on the right. (You may need to scroll down.)
Note: You may need to enter your password to access the New Account window."
We look forward to your reply.
Cheers!