problems leaving voicemails

[KatBot]

I have had an S7 for a few months now. Just recently I started having trouble leaving voicemails for some people. When I call my parents home phone (not a cell) if they aren't home it rings a few times then goes dead. I get no outgoing message, and can't leave a voicemail. The same thing happens when I call my BF's cell phone (he's on AT&T as am I). I think it has to do with my cellphone since when I use my home phone (VOIP) I don't have these problems. I don't actually make many phone calls so this may happen with other phone numbers as well & I just haven't found out yet. Very puzzling & also annoying. Hoping someone out there has some good ideas! Thanks