It looks like you are doing something wrong in the kamailio configuration.
Mar 21 09:56:18 ap07stvp.xxxxxxx.xxx docker[504]: 29(33) ERROR: {1 28031 BYE uugl1base9cfpp1va073} <core> [core/resolve.c:1730]: sip_hostport2su(): could not resolve hostname: "o4s18f05d8bv.invalid" Mar 21 09:56:18 ap07stvp.xxxxxxx.xxx docker[504]: 29(33) ERROR: {1 28031 BYE uugl1base9cfpp1va073} tm [ut.h:309]: uri2dst2(): failed to resolve "o4s18f05d8bv.invalid" Mar 21 09:56:18 ap07stvp.xxxxxxx.xxx docker[504]: 29(33) ERROR: {1 28031 BYE uugl1base9cfpp1va073} tm [t_fwd.c:1759]: t_forward_nonack(): failure to add branches Mar 21 09:56:18 ap07stvp.xxxxxxx.xxx docker[504]: 29(33) ERROR: {1 28031 BYE uugl1base9cfpp1va073} sl [sl_funcs.c:418]: sl_reply_error(): stateless error reply used: Unresolvable destination (478/SL)
This issue tracker is for discussion bugs and and new features related to the code, and not solving configuration issues. Please contact the sr-users mailing list for that [link](https://lists.kamailio.org/mailman3/postorius/lists/sr-users.lists.kamailio....)