It's even easier than that. In @HungryPanda's case, the ZSA was internally wired properly, but 1 of the jacks was simply installed backwards. So all you have to do in that case is open the back, flip the offending jack around 180 degrees, and reinstall the back. You only have to resolder when it's internally wired wrong. Someone recently had a ZS10 that had the BAs soldered out of phase. The only way to fix that particular issue is open them up and resolder them the right way.