PPPoE reconnect fails after interface flap
It seems there is a race condition where pfSense loses track of the PPPoE connection following an interface flap. It does not keep attempting to reconnect after failing to do so for a couple of times. Reachability to the ISP had been restored as can be seen from the log. Manually triggering another interface flap seems to restore connectivity.
May 11 22:58:11 pfSense ppp: cannot open pid file: No such file or directory