Found the problem, one feeder and the single piece of track were still showing continuity between hot and ground. Tracked the feeder along the layout and found a spot where it was "stuck" Some dummy put a screw right through the middle of the wire hole in the support when attaching the plywood road base.
Been that way for months.
Screw has been moved and wires fixed. Time to reassemble the loop.
Definitely would not have tracked this down without the continuity meter.
