Asus AIMesh and other Mesh will likely use different channels. Imagine a 3 person conversation, where a person is talking to one of two different people and those people are answering back. If the two people are on different channels you can only hear one at a time. If they are on the same channel, then they both hear you at the same time and you hear them both at the same time

That is interference and will result in poor connectivity. In order for the setup to work properly, any AP on the same channel should be far enough away from each other that they can't hear each other.

From earlier, if each of the two you are talking two are on opposite sides of a football field, they can both talk at the same time, but you are only going to hear the one you are closer to.