@PatchyFog thanks, got it figured out. Took a multimeter and a few hours of trial and error. Ended up being the 4 way paddle switch from Amazon. The switch pattern is not same sides and the...

@Chicago_SH hello. Recently installed according to drawing. Left the 4-way switch alone and only added TP-Link 3-way switches on the other two locations. Problem is that when I flip the 4-way switch...