This is a regression of 107900, which addressed the following sequence of events to reproduce:
This was fixed early in 2.x but appears to have regressed somewhere along the way.Here's what I did:
- I have some mods enabled
- I chose multiplayer -> host saved game
- I selected a save with totally different mods
- the hosting window opened, allowing to set up server settings
- after validation, the save loaded without the required mods, keeping initial mods. No mods sync window was displayed at any point.

