Cannot receive incoming calls on landline

For quite some time, we cannot receive calls. Phone works fine for outgoing calls. Incoming calls make a half ring, then disconnect. Problem began at time new neighbor probably set up phone service. Complication: prior to home purchase, neighbor's house had same address as we do, due to a previous property split. Don't know if this may be a factor.

Technician came and said no external problem. Have tried troublshooting all ways possible and cannot find a problem. Service interface box is so old, it does not have a jack to try a phone at that point. There is only one primary phone jack in house. Have thought about replacing this jack, but still think this is an AT&T problem as our phone system worked fine for 11 years. Timing w/ new neighbor seems too coincidental.

Has anyone had this problem and come up w/ a solution w/o hiring a phone technician?