Is it possible that achievements don't unlock? For example I have finished Europe and America, but also Fotgotten doesn't unlock.

For some reason 4 achievements did unlock, but I'm unable to unlock anything after that.

So today a few achievements have been unlocked. Even ones that shouldn't be unlocked

It's possible that firewall / anti-virus programs can affect GOG Galaxy communication (meaning time tracking and achievements may not necessarily work), and this can happen with any game. But, I did notice that all of the 'number of stamps collected' achievements unlocked way too early, and the achievement for building a level with 300 rail tiles unlocked for me even though I never built anywhere near that many.