I've seen that as well what you described. But if they don't need to fight, they won't fight.

If there's a door near by they will attack it, simply because it's in range of their aggression radius.

they leave other units fighting, because they healed them and the other enemies were out of their aggression range. So they decide do go back to your dungeom to refill their needs, and when there's something at their way home which is in their range of aggression, they will attack it.

The Situation you describe is simply that the cultist haven't anything to do there, because the other things are out of range. The priority to refill needs and patch himselfe up is higher.

on the way back he saw a Door which is in his range of aggression, so he will attack it, because fighing the enemy has a higher ptiority as refill needs.

How I said earlier, we could increase the range of aggression, BUT that would lead to range units are hunting other units and moveing off.

So perhaps a slight increase would help, which could cover as 1 or 2 units, but IMHO it's good how it is right now.

Behaviour is intended, no bug, but perhaps an improvement idea.

Minions who haven't satisfied needs or low HP will go back to your Dungeon, especially when there's no rally flag.

And they will attack minions and defenses on their way back.

Behaviour is intended.

we could increase the radius, where the range units are attacking while they aren't rallied.

Cultists also heal the units of your opponent, while attacking ;D (allready reported)

Further investigattion:
I can confirm that, The Chunder and Fire Breathers Breath and burb attack wont hurt any door at all as well as Inhibitor and Dungeon Cores.
Cultists also cast their debuff (- movement & attack speed) onto doors.

In generall, I do not dislike that Units casts non-usefull Abilities onto Things, because they will level up, but they should definatly prioties other Units over un-effected things to use on their abilities.
(Tested it with Chunder & Fire Breather on Dungeon Core and Workers)

Could it be that everything with no attacks are immun against all Damage debuff attacks?

Perhaps debuffs in general?

I would also test that with a cultist, attack once with normal attack, them Debuff, attack with normal attack again.

No, I'm a Human who have to reproduce you're tickets.

There's nothing to reproduce for me, so we need your output_log to investigate it further

did you tested it with a lvl 1 Chunder?

Because the burb attackbid mostly for debuff.

@Noontide

we had such a ticket from Slich interally, perhaps he can confirm that?

Because I tested it allready with lvl 10 Units, and they little deal damage

Many Preplaced rooms which are get converted haveing such 1 tile mess.
Almost every Campaign level I can think of is effected by this.

I can confirm that for every other aspect of the game.
MP, Skrimish, Survival, Campaign etc.

Can be exploited with the scrolling up during the loading screen.

Please upload output_log when such a thing happens agin, then the coders can take a look at it.
Thanky you :)

Can't confirm internally.
Please upload output_log and savefile