Why is the system wi-fi prompt going to a non-logged-in user?

After starting to use a new MacBook Pro with El Capitan, I'm having trouble connecting to wi-fi at a cafe I normally frequent.

Specifically, I've noticed that the wi-fi icon in the system menu bar shows that I'm connected with full strength, but I have no internet. I also noticed that OS X never prompts me to join the network.

However, here is a clue I noticed: when I tried switching to a test user on the same computer, I noticed that the system prompt to join the wi-fi network was visible there. So it seems like the issue is caused by Mac OS X displaying the wi-fi prompt to the wrong computer user!

When I click "yes" to join the wi-fi network using the test user, and then switch back to my original user, I find that I can use the wi-fi network normally.