One of my contacts on my S7 has two home email addresses. One is correct. I can't delete the bad address. There's no delete function when I try to edit. A long press gives options to copy to clipboard or set as default.
Tap edit that is at the top of the screen, then the options to delete will show up. Be sure and hit save after editing.There is no minus sign on the right edge. Instead thee is an "@" which puts me into email.View attachment 234588
I'll let B. Diddy see if he knows more, but..It doesn't show up on the screen shot because I obscured the personal information, but the email addresses are greyed out, as are the other descriptors on the right (home, other, mobile) and they are not editable.
I don't save contacts to Google, nor do I use gmail. I avoid the cloud as much as possible. I do sync with Outlook, using Samsung Smart Switch over the USB cable.