Why cant people hear me if they call me?

To start off I have Sprint. I have an iPhone 6S Plus running on iOS 11.1.1, newest update. I’m having this peculiar issue where anytime someone calls me, my phone rings and I see caller ID, but when i pick up nothing happens. Just silence. My mom tried calling me and she said that “There’s just one ringing tone and then when you pick up, it’s all quiet.” So I tried calling my mom back immediately, and if I call her, then there are no issues. We can hear each oher fine and theres no drop or anything. Signal is very good where I live and I’m just very confused and frustrated with what’s going on. I’m supposed to be having my car towed and since I cant receive calls, the call has to go through my parent, in which case my mom will text me what I need to know. It’s a a mjor inconvenience to everyone so I would like to get the issue resolved as quickly as possible. I’ll be looking for solutions throughout the day, but if anyone has experienced anything similar, please let me know what you did to remedy the problem. Thank you.