AI gets stuck

Hi, my game does not existing in a flat xyz coordinate. It’s more like a planet, a spherical coordinate(if that matters).
When enemies are chasing the character, sometimes AIs bump into each other. Since all actors move based on addRelativeOffset in my game with sweep on, they will just stop if two AIs touch each other and both try to move toward the player. What would be a easy and low-cost algorithm to fix this?? Turning sweep off is not an option because enemies overlapping each other will look so crappy…