Since one switch works normally and two don't, the problem is definitely in the switches.

Take the problem switches out of the layout and power them up with just 2 pieces of track connected to each leg of the switch and see if the problem still occurs. If it does, there is an internal problem in the switches.

The 1121 switches do not have fiber pins in them, unless the switches are set up for automatic operation.

There is no polarity in AC voltage, so the wiring to the track from the transformer is not an issue.

Confirm that all switches operate properly outside the layout.

What transformer are you using?


Larry