GEM needs replacement?

The switch that was the reason of the recall failed and that failure allowed brake fluid to leak into 3 wiring harnesses located below it. If the mechanic did not check those wiring harnesses and plugs for brake fluid and or damage caused by brake fluid, they may be wet and causing the issues you described. Not only should the mechanic have checked them, but he should have replaced the harnesses if they were full of brake fluid due to this issue having caused fires and electrical issues. I did my own repairs on the brake switch and cleaned all my wiring using brake cleaner and electrical contact cleaner. Before I did, I had the same issues you are having. Hope this helps.