I have not been able to get the bug to occur yet but I added some more logging and pushed v9.1. Once this is live you'll notice an increase in the amount of stuff logged when the bot should be attacking. If the issue arises again the new logger information should help narrow it down, in the mean time I'll keep testing to see if I can replicate the bug.
Edit: Just got the bug to occur, no idea what's causing that behavior. It appears the script just stopped looping entirely.
Edit2: So I think I found the cause of the bug. If you're fighting a Chaos druid and another spawns on top of it and it dies the script just stops working, at least that is what happened for me. The script will start working fine again after I pause and unpause the script. The reason you likely don't notice this at Edgeville is there is a significantly larger area for the druids to roam in and thus this scenario is far less likely to occur. I pushed an update, 9.2., which should hopefully fix it.