Hmm, what FreePBX/Asterisk version do you run ?
(because, last time I read, chan_pjsip is for Asterisk 12 and over, and that is available in FreePBX 13 which has ‘only just’ been released to beta status…)
What’s your issues on currently running versions? because FreePBX 12.0.70/Asterisk 11.4.2 I run in D&E mode and am not aware of anything nasty ?