I had three crashes this morning on a divide-by-zero, for example at abstract_jb.c:1008 in 14.3.0.
Does this ring any bell to anybody?
This is quite odd. I took a quick look at the code at that line number and it appears the divider should never be zero, but somehow it got set to or initialized to that maybe.
This does not sound familiar. Please create an issue on the Asterisk issue tracker  and attach a backtrace . Debug logs around the time of the crash may be helpful too if you have those. Which channel type (chan_sip, local channel, chan_pjsip) is involved, and how you are enabling the jitter buffer (dialplan function vs configuration) would be good to know as well.