Actually, the source of this glitch has been recently figured out.
If a city has 99 grievance, it will stop at 1 loyalty. If a city is at 1 loyalty, it will be unable to gain any more grievance. So, if you grieve a city to 99 (or less if there's a tax rate in the target city), the city will halt at 1 loyalty.
The solution is easy. Some people stop the loyalty grind when you pass the 15 loyalty threshold, and attack once every 6 minutes.
DO NOT do this!!! Keep attacking with spam waves. You won't take loyalty down faster than 1 every 6 minutes, but you can still add to grievance. You need to get the grievance to 100
BEFORE the loyalty gets to 1. Just attack and get 100 grievance as soon as possible, even if the loyalty is still in double digits. With 100 grievance you can take the city once the loyalty drops from 1 to 0.
Let's say you grind grievance up to 100, by the time loyalty has dwindled to 10. You can then wait 60 minutes (give or take a few minutes depending on when the 6 minute "tick" is in relation to your last attack). Then just send one attack and you will take the city that has grieved itself to 0 loyalty.
I hope that helps.

Bookmarks