So I'm 116 hours into a map, my biggest base yet. There are attacks and so on, but there were also so many inactive groups of enemies that the game was slowing down till I consoled them. This is the only enemy modifier I use atm. Some were stuck around cliffs, some were stuck on open land. Some possibly left overs from artillery bombardment of spawners, others are possibly enemies that decided not to attack a base.

Is this behavior pure vanilla, or is it possible that rampant loses control over some units, or is it some variant of retreat?

In other news, they like hunting my trains. Which is ... correct, but forces me to laser turret wall some stretces :D

Do you have a save game?

https://www.dropbox.com/sh/uusb7y49lxs03x6/AAC354XGjCqlaxKj8g5PwwX_a?dl=0

East southeast iron 10 has a lot of enemies standing around it. I will leave them in peace when I continue playing, and keep an eye on them.

They do leave at some point, not sure when or where, or whether they ended up attacking.

This is most likely Rampant's fault, but I don't know If I can fix it.

The factorio game engine sometimes eats unit groups that fail to move to many times and leaves the units behind.
Those units by the ESE iron 10 aren't in a group at all and just loose units in a area.

I kept a close eye on the loose ones close to iron 10 (south and east of it), and the ones that didn't wander too close to the lasers were deleted after some time. At that point the two groups just NEE of iron 10 were still there. They are still there in my latest save, more than an hour later.

The groupless ones thus seems to be non-problematic, but those two groups might indicate something, unless I misunderstood something. Unless the two groups also are groupless and somehow immune from automatic cleanup?

You are right, there should be a bug fix soon

this should be fixed now

Thank you :)

I found unit groups still occasionally disappear when testing current version. No save, but will grab one next time it happens.