Why are the two Cecil columns pinned to the top of the “Recent” frame?
Is it a bug or a feature?
A feature. Each column is pinned globally for 2 weeks. They unpin automatically when I do it correctly. 
There are some prior threads on this. I’ll find and link.
This can be helpful:
How to subscribe and get an Email for new columns by Cecil.
Click on the category (forum), Cecil’s Columns/staff Reports
Click the bell icon button to the far right, after the New Topic button.
I recommend selecting Watching First Post as this will let you know when a new topic is started in this forum.
If you click on the pins, they’ll turn over, then they’re unpinned and will move around based on your settings, like any other thread would.