[HoosierDaddy]

If we go back to what changed, it takes us to the mysterious issue showing up just after the contractors were replaced.  I would double check my wiring on the contractors cause if the neutral and hots were crossed up it could easily explain what you are seeing

Whatever the issue is now must be related to, or the result of, whatever caused the contractor to fail in the first place.

Yes that is what I'm trying to understand. Did something fail causing the braided line to be a temporary conductor? Was that the initial "chatter" noise. If so the contacts could be replaced correctly but there's a problem somewhere else that is blowing the fuse. That is why I would advise caution if there is still some stray voltage that the braided line offered a temporary ground to.