I have this weird problem where I can send texts to or call a friend of mine but she never receives it. On my end, texts show up as sent and when I call, I hear it ringing and then eventually voicemail.
This happened to me once before with a different friend. Both of them use iPhones but I can also contact other people with iPhones without any issues.
Another weird part of this problem is that if I send a group text including that friend, she will receive the text, just not any individual texts only to her. I can receive texts and calls from her with no problem.
Phone: Samsung Galaxy S5
OS: Android 6.0.1 (also happened on an earlier OS)