It appears that Al's assessment may
be correct that particularly because of the apparent orientation of the
electrode when I screw it into the hole ending up such that the apex
hit the curved back part rather than the end pointed toward the center
electrode. It appears the apex seal did bounce over that curve part
for a while and either the apex seals finally gave way or the springs
under them did. Perhaps Lynn would know if its possible to break the
springs while leaving the seal intact.
Could the seals be bent to the point they no longer can more freely in
the grooves?