A known issue is the folded tab connections inside almost every fastrack item. This goes back to the days of the older Lionel Tubular switches, those folded tab connections are best soldered to ensure good electrical contact VS hoping, praying that the limited pressure from a bent tab and stamped metal plates makes an electrical contact- let alone carries multiple Amps of track power.
Bulletproofing switches 101.
While this picture is from a damaged switch from mislabeled aux power wiring, the folded tabs of the ground plate at the end of the switch are seen in this photo as stock. They depend on that crimp of the folded tab making contact and over time that can and does tend to loosen and fail.
The center rail follows a more critical path with several in series contacts and plates to get from one end of the switch to the other.
This just shows some of them in the center of the switch
Again, not completely surprised on a stock switch without any "bulletproofing" soldering modifications to see it fail after passing likely high current current during a typical derailment.
