It is now happening to me also - i use Chrome and win 10. No point in being here this evening it is happening so much. I also open a separate window for Settlers.
Edit
In the last couple of weeks the game kept freezing and with a 'disconnected from server message'. It would happen after being in the game at least 2 hours and being AFK for a while, so i felt it might be a new thing to solve traffic problems on the server. I would remain however on the internet uninterrupted in other applications .
But this freezing is different. I am not now getting any message at all not the server one or flash. The game just stops But again other tabs remain working for other applications. Last night when i first posted it was occurring every few minutes. I do a lot of work for the guild in google documents and they were saving perfectly so no internet connection drop at all.