Even APs need their “personal space”, yo.

Um... I think those should be further apart. pic.twitter.com/Yvc6BimJfl

— Jake Snyder (@jsnyder81) March 6, 2015

And even when on different channels - being too close - can cause interference - ADJACENT Channel Interference.

Put some space between your APs, bruh! (How much, you ask? 2 meters should do.)