Receiving ghost calls from people in my contacts

I have been receiving calls from random contacts. I have been receiving the calls any time of day but lately its been around midnight and even 3am. These people are not actually calling me. For example one time I received a call from my mom who was standing right next to me and definitely not calling me. When i answer, its silence. Turning on do not disturb and only allowing contacts to call me doesnt actually work since the calls are coming from the contacts.