Hi everyone, luckily I found this thread. I also have a 2015 WRX and a 4100nex. Same issue. Sometimes it starts up immediately, sometimes it gets no power at all for x amount of time before turning on. It is very random. I noticed a lot of us have Subarus or gt86( frs may have subaru parts). I think it has to be something related to Subaru either the battery they use or how the ignition system works. Btw, I do not have push start.