When my friends and I play, at the end of the game, sometimes (like 30% of th etime) we all get logged out and then we can't even see points because it doesn't display the game history. Anticlmactic end and totally unsatisfying.
On what platform are you playing? Desktop computer? (What browser?) Laptop. Tablet? Smartphone???
On my desktop--Mozilla Firefox--(the only way I have played), I always get the final summary screen that you say is sometimes missing when you and your friends play games.
I suspect (hope??) that, once we know your platform, someone here will be able to suss out the problem you've been having.
This happens to me as well using Chrome/Firefox on Linux. Also on Firefox on Windows. I believe it happens whenever you guys put out a new build. (which happens quite often these days)