No sound when placing and receiving calls

When receiving a phone call, the phone vibrates but there's no notification. When I answer, neither person can hear anything.

When placing calls, the call screen doesn't pop up and I don't hear any ringing (but it does connect the call). When the person answers, neither of us can hear anything.

Currently running Resurrection Remix OS, Beast Mode Kernel, TWRP.

I have also tried rooting, un-rooting, factory reset, replacing the boot loader, replacing the ROM, and replacing the kernel.