When receiving a FaceTime call from my girlfriend I pick up and it’s not her.

I was having issues connecting on a FaceTime call with my girlfriend. I reset my network settings worked for a little and we lost connection. I then turned on WiFi roaming, and connected my email to my FaceTime to try and call her through that. I also tried calling through my iPad. We finally end up connected but as I’m on the phone with her on FaceTime, I get a FaceTime call from her contact, I pick it up, it’s her, this keeps happening right. We get freaked out and hang up. Then I receive a call from her number, and pick it up, it’s a black screen not saying anything. I hang up. Her contact with her name calls me again I pick it up and I see a blurry image like if someone is covering the camera. I ask her if she called me, and she did not. I’m not sure if my Apple ID is compromised, I changed the password and added the security key. Turned off my FaceTime, turned it back on and called her and she picked up fine. Then I get another call from her contact while on ft with her and pick it up and it brings me back into a call with her. I don’t know what is happening.

this is a call from her contact but it’s clearly not her.

this is me getting a call from her contact while already on FaceTime with her, but she did not make it and it’s not even possible to call while on a call without ending it first.

I changed my Apple ID password and she changed hers but it happened again when I was on FaceTime with her, got a call from her picked it up and it brought us back into a call, but why is this happening?