Enemy AI navigation broken on earth defence maps.

[BiccyBiscuit]

During just about every game I play on this map rather than actually protecting the target I always end up having to seek out the enemies as they get stuck on these area their AI doesnt seem to understand where they jump onto a crate and onto a platform leading to the defence target. these locations are very obvious and easy to find as they often have about half a dozen enemies bunching up jumping up and down the crate rather than onto the platform from the crate.
there are multiple areas that this happens in.