I noticed that my lower right side GI was out on my otherwise mint GOT premium. Raised the playfield and saw that the GI wire bundle that serves all of the lower GI had been crushed and cut wide open by getting caught in the coil that raises the "lord of light" drop targets. I cleaned it up and moved the wiring further away from that coil and resoldered the damaged wires and everything works fine again.
Might be worth lifting your playfields and take a look at the yellow-black / white-black lower GI wire bundle as it goes around that coil!!