Prolific : 0 place remaining

I recently joined the website, and at the beginning I was getting a lot of studies from the prolific google chrome extension.

Recently, I am getting maybe max 3 notifications a day, which is totally fine. However, by the time I am at the study, there is no place remaining. I have pinned the extension and I am being very quick but yet again mostly unsuccessful.

Does this happen with other people?
Does anyone have any advice, previous experience?