If you make a chain of pylons, and then destroy one of the pylons in the chain, any forward pylons that are now disconnected from the core remain active (maybe because they now supply power to themselves after getting kickstarted?).
However, upon reloading a save, the bug fixes itself and the disconnected pylons become inactive (probably because the pylons start inactivated and try to reactivate in the split second after loading).
P.S. It would be nice to have a tag labeled "gameplay" for bug reports