Why isn't prolific giving me studies anymore?

I have only gotten like 6 studies so far, and all of them had been on a Saturday. Then I never got anymore.

I have the prolific notifier installed on Chrome and usually, after being AFK for a while and coming back to my laptop, I see a "!" on the extension icon. What's that supposed to mean? Does it mean that I am logged out of Prolific or I missed a study?