I am new to PJSIP, we have in the past month moved to Asterisk 16 and migrated from chan_sip to PJSIP.
Chan_sip monitored my extensions and tracked its state, from UNREACHABLE to Reachable and also Lagged. Does PJSIP have the same type of logger available?
Yes PJSIP can log things like that, but if you are not seeing anything then check your other logger settings eg. /etc/asterisk/logger.conf, file permissions, etc.