We have 2 phones in our office, both of them Panasonic KX-T7633 with 4 lines each. Lines 1 and 2 are rollover. Line 3 is a dedicated fax line and line 4 is dedicated to our 800#. When someone calls in to us it will ring on line 1 and/or 2 depending on if someone is using line 1 on the other phone. When we make a call it used to be that line 1 would automatically light up for us to make the call out on or line 2 if someone was on line 1. Out of the blue line 1 and 2 are no longer available to us to call out on, the phone automatically chooses line 3. If we try to force the phone by pressing line 1 or 2 to use to make a outgoing call the receiving number is not available to us and we get a message stating the phone number is no longer in service. When someone calls in to us the phone still operates as normal choosing line 1 or 2 for us to answer. Apparently the problem is only on the out going end. Any ideas how to resolve this?