Point

You can check whether your tickets are being added by clicking on your name on the right end of the black menu bar in the Arcade.  On the tabs that come up, click on Rewards History.  That will bring up your ticket history.

The only reason I can think of for the message you’re describing is that you aren’t actually signed in when you’re playing the games.  If you are not signed in, you will see a pink “Sign In” box where your name should be on the menu bar.  

If you are still getting that message when you’re signed in, you probably should contact the Arcade Team.  You can do that by clicking on “Help” on the Arcade menu bar and going to the very last item.  Give them as much detail as you can, such as what type of device you’re on, what browser and/or operating system you’re using, which games if it’s only happening on some, etc.  Unfortunately, they don’t work weekends, so you probably won’t get a response until Monday or Tuesday.