Reinvite issue with chan_sip

Using Asterisk 17.8.1 with chan_sip still, we got this SDP in a reinivite:

v=0
o=inbcf 1259978033 1 IN IP4 10.1.7.32
s=inbcf_1487523396
c=IN IP4 10.1.7.32
t=0 0
m=audio 49182 RTP/AVP 0 8 96
c=IN IP4 10.1.7.86
a=rtpmap:0 pcmu/8000
a=rtpmap:8 pcma/8000
a=rtpmap:96 telephone-event/8000
a=fmtp:96 0-15
a=sendrecv
a=rtcp-mux
a=msid:73dddf099b1b49e1a6241f718eaadcae 810481d7814041e78c505876e1c91539
a=ssrc:609209133 cname:yTmKgLCcCbbh
a=mid:audio

Asterisk continued to send to 10.1.7.32 even though it should be to 10.1.7.86. According to the company that sent it, the spec says it should be the 86 address. Does anyone know if that is the spec and if so is Asterisk known to have an issue with this?