The loose_route function from the rr module is always getting an error in the logs that's not able to find the socket when the BYE request is coming from Kam to the Teams:

Feb 24 18:20:58 kamailio kam[24681]: WARNING: {BYE (1) | Seq=102 | Source IP=192.1668.1.1 (udp) | Call ID=2e701c07f99c5cb89fc72db225a6e309} rr [loose.c:800]: rr_do_force_send_socket(): no socket found to match second RR (sip:sbc-fqdn:5067;transport=tls;ftag=4ccd608c55e94f4aa094151dfd9e23a4;lr;r2=on)

This is the BYE message:

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====================
tag: rcv
pid: 24681
process: 3
time: 1614190858.750938
date: Wed Feb 24 18:20:58 2021
proto: udp ipv4
srcip: 192.168.1.2
srcport: 5060
dstip: 192.1668.1.1
dstport: 5060
~~~~~~~~~~~~~~~~~~~~
BYE sip:api-du-c-euno.pstnhub.microsoft.com:443;x-i=58a922ac-934d-49cb-93b0-a7b435a36ea5;x-c=2e701c07f99c5cb89fc72db225a6e309/d/8/7776d3cf84d340a79f0a433d743e7a1a SIP/2.0
Via: SIP/2.0/UDP 192.168.1.2:5060;branch=z9hG4bK24411a29;rport
Route: <sip:192.168.1.1:5060;ftag=4ccd608c55e94f4aa094151dfd9e23a4;lr;r2=on>,<sip:sbc-fqdn:5067;transport=tls;ftag=4ccd608c55e94f4aa094151dfd9e23a4;lr;r2=on>,<sip:sip-du-a-eu.pstnhub.microsoft.com:5061;transport=tls;lr>
Max-Forwards: 70
From: <sip:+1234566789@sbc-fqdn:5067;user=phone>;tag=as72ae570b
To: user1<sip:+87654321@sip.pstnhub.microsoft.com:5061;user=phone>;tag=4ccd608c55e94f4aa094151dfd9e23a4
Call-ID: 2e701c07f99c5cb89fc72db225a6e309
CSeq: 102 BYE
User-Agent: COMPANY
Content-Length: 0

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====================

The domain from the second rr (sbc-fqdn:5067) it's perfectly valid and resolved from the kam server and from outside.

version: kamailio 5.4.4 (x86_64/linux) bdf4e0

Any thought here?

Thanks