So there's a person I'm trying to get a hold of. She has an Android and I have an iPhone 6s on ATT. I believe she has Verizon in Florida. Whenever I call her, it makes the error code beeps. Whenever I text her, it goes through but she doesn't receive it. She has even texted me 4 times. I haven't received one from her. I've tried restarting my phone. Should I try a carrier update or removing and reinstalling my SIM card? Thank you.