Additional détails :
We’ve used Asterisk PBX for years and experienced this bug (DTLS packet from 127.0.0.1 dropped) as soon as we upgraded to Asterisk 20.5+. We urgently had to patch res_rtp_asterisk too - the same lines - to disable this drop if ip address was 127.0.0.1.
We did not post a bug report because we were using Asterisk 20 + chan_sip + ICE/WebRTC. But since we just switched from chan_sip to PJSIP, the DTLS packet drop still occurs with PJSIP.
So +1 for a fix