Agency Population keeps dissapearing

[YodaDoge]

So in several savegames i notice for some reasons all the agencies lose alot of population suddenly for no apparenty reason.
Im not talking about belivers it is the total number of population just drops.
For example after 2 years city of abundance has dropped to 47k total people leaving me with 10k followers while i previously had enough to build a wonder.
Is this a malfunctioning mod or is there a real reason for it?
Of course there we no unresolved disasters and the city stability is prosperous too.
This also happens in every agency at the same time.

[CaoLex]

If it's something like a village then it's probably just earthquake events.
If it's city, then it's most likely other factions massively out-influence you.

[Kachlicka]

This happened to me too. I do use mods.

When it happened to me I realoaded the last save with the correct population numbers after removing two mods affecting agencies that I did not care about (SkillLevelInRecruitment and City Event Helper) and so far so good. That does not really mean anything though.