Missed Facetime not appearing in call log

Basically every so often, I will receive a FaceTime call that I will miss. I will always be around the phone when it happens, but just slightly out of reach. My phone will buzz and ring, and it will light up the little FaceTime icon in the corner (it will not display the incoming call screen, so I don't see the name of the caller), so I am aware of the calls. It's just, if I unlock my phone and check the notification, it will open my call log with no newly missed calls. If I check my other sync'd Apple Devices, they also don't display a newly missed call. How can I find out who calls me, and how can I fix this issue?