So this has only been happening to me the past couple days...
When I click the X to log out, it gives me the "are you sure" message like normal, but even if I click "yes", it never actually closes the client. I've had to close it manually the past 4-5 times I've logged out.
You can see in the attached, first it shows my mouse hovering over the "yes" option.
Second pic shows the cursor just below the dialog box (the clock). It stays that way no matter how many times I select yes.
Haven't tried selecting "no" yet... will update after dinner.
Haven't repaired client, and would like to avoid doing so if possible