Default unrest, weird stuff

[Ilmater]

I am playing the Vanilla campaign as Milan and currently control 10 regions. I notice that the game seems to have this in-built mechanics for settlements which do not belong to your home faction originally to develop default unrest levels regardless of your actions to counter them.

For instance, cities such as Dijon, Florence, Venice and Naples under my control all have a permanent 15% unrest while castles such as Bern, Cagliari and Palermo have 10%. Settlements assigned under the home faction of Milan in the descr_regions.txt which are Milan, Genoa and Ajaccio however don't have this default unrest.

By unrest I am referring to the pitchfork icon unrest which isn't related to religious unrest. I am certain, after doing various testing, that in the above cases they aren't caused by

1. Sneaky enemy spies instigating the local population, as my counter-espionage efforts have more or less weeded them out completely.
2. Rebellious knaves/foreign invaders hiding in fog of war devastating the countryside.
3. Initial high unrest levels upon occupying an enemy settlement as I have been controlling them for ages. Sacking/exterminating seems to remove the unrest for a certain period of time (seems to be a few turns) but eventually the 15%/10% will reappear.
4. Generals with traits such as Prim or HarshJustice which cause unrest. I've taken these into account.

The default unrest seems impossible to remove and is a rather irksome feature of the game. This is more of an observation rather than question. But is anyone else experiencing the same problem as I do?

[Player989random]

Yeah but I just built brothels instead of anything else. If that doesnt' work also build the mayor's palace.

[pwijnands]

Everyone is experiencing the same problem as you. It's game design that all but a few regions have unrest. Your observation of starting regions plus a few adjacent regions don't have this unrest.
Technically all regions have a hidden faction assigned to them and any other faction taking over will suffer a fixed unrest problem. There is a file (which can be modded) that assigns a value to all regions.

[Ilmater]

Ah I thought so, guess I'll just have to learn to live with the insurgents then. If all else fails I can always resort to extirpation should they have the audacity to riot.