Hi,
I have been playing with a friend since version 2.4 and we had several desync issues. The game is stable until about turn 40 and then it desyncs about all 10 to 15 turns.
After the release of 2.5 we started a new game, but it does not seem to have changed, the problem persists. It does not seem to matter if it is run on a timer or with manual end turn.
All available DLC is enabled.
If you can tell me where to upload the Zip files the game creates I would like to help and upload some.