2 bugs or so its seems

[davidus terrus]

while starting 2 new campaign as rome, i stumbled upon two game breaking bugs i believe, or maybe mechanic not intended

after 2 turns i conquered etruria and only took occupy, the next turn latin culture had plunged 40 + % and was sitting at 14 and italic had jumped to 80+

retry next campaign, i took etruria 2 turns everything is fine now except one turn where latin culture went down 2 % sitting at 50% then turn 4 while i had 2 army sitting in southern italy ready to conquer taras next turn, epirus launch a rush attack to beneventum, its ok i can recover it with one army from the south, so i take back the city, but all patrician , plebs, and proletarii, had dissapeared leaving 32000 perigrinis in the city alone.so they took the city and bam all my population dissappear and they colonize with 32000 foreign population straight away? i call , i gave up for my new campaign

[Dresden]

When a faction takes a region that does not have their dominant culture, the population will change to mostly foreigner.

I am not sure for the culture reason, the game calculates that on its own. It looks to find a ratio % that matches the bonuses in the area.

[Plush_Salmon]

so i take back the city, but all patrician , plebs, and proletarii, had dissapeared leaving 32000 perigrinis in the city alone.so they took the city and bam all my population dissappear and they colonize with 32000 foreign population straight away?

That is actually Your own pops. They were considered foreigners by the invaders, due to their culture not being dominant in the region, thus - assigned to the 4th class.
After reconquering You're still royally sre.ed, becasue there are no roll back mechanics for stuff like this.
P.S. Can I have a save? I would like to dive back into DEI and only appropriate start would this save, full of suffering.

[davidus terrus]

That is actually Your own pops. They were considered foreigners by the invaders, due to their culture not being dominant in the region, thus - assigned to the 4th class.
After reconquering You're still royally sre.ed, becasue there are no roll back mechanics for stuff like this.
P.S. Can I have a save? I would like to dive back into DEI and only appropriate start would this save, full of suffering.

no sorry i forgot the good saves,i restarted a new campaign plus i use some submod, nothing that changes population or culture though