Bug - No attacks in Shal'Dun

[Amaror]

So I encountered a problem in my Breath of Winter playthrough. When I play the Map Shal'Dun the cities don't attack me. That doesn't seem like a huge problem normally, but it makes it almost impossible to farm the coins necessary for the chests in the map. I like to complete games, so I would prefer to get them.
The first time I encountered the problem I thought it was due to the way I played it. I entered the map and left it immediatly after the cutscene for a sidequest. When I noticed that noone attacked me I reloaded I earlier save.
I just started the map again now and again, noone attacked me even though I haven't left the map since first visiting it.
I noticed that I can farm the enemies somewhat by conquering their cities and leaving some units on hold near their spawning buildings (on hold so they don't destroy the spawners). Sadly can't use my avatar for this since lena will destroy the spawners. Would be really tedious to setup though.
Is this bug known and if yes, can it be worked around in some way? Would prefer to play the map with attacks even if I have to restart it a third time.

[Tam Glengoyne]

Don't know what to do about not being attacked, but here is a glitch; you can open the chests without the coins.
Send a hero to stand near the chests and approach the entrance to each room in 3rd person. Not too close, just close enough to see if the circle is red or green. The chests your hero is close enough to will be open without coins. This works in all three chest chambers.

[janthailand]

you trigger the spawns and attacks by starting the first monument
right where you have the dialog.
i usually decline the offer and dont start that monument,
but instead go solo all over the map and start the other monuments,
and when i have an army on each spawn on hold, i start the first monument.

actually these days i dont bother that much with farming,
i can open the chests in 3rd person by having a hero standing next to the chest and
stand some 10 meters away, and i get the experience from modded maps