I was happily using Quicksilver for a while (mainly using the clipboard),. For some reason I got out of the habit but now I need to reactivate it. When I was using it before the Clipboard history window stayed open until I closed it, but now it closes by itself, sometimes so quickly that I haven't found the entry I want to paste before it closes.
Some particulars:
1'm running OS 10.13.2 on a MacBook Air that claims to be "early 2015", though I bought it much later than 2015 (probably 2018)
I'm trying to paste into a file created by TexShop 4.21, which is generally very well behaved and not on your list of applications that don't like Quicksillver.
The Clipboard preference window has just three items (should there be more?): Capture history (checked); 20 items; Hide after pasting (unchecked, but I don't see an difference in behaviour whether checked or unchecked). I installed the plug-in today, so I suppose it's the current version.
I'm using an AZERTY (French) physical keyboard, I have the U.S. keyboard available in the menu, though I normally never use it. The keyboards available in the keyboard are the standard French keyboard, which I normally never use, and three custom keyboards. The one I use for LaTeX is active at the moment and has lots of special keys, like option-S for \subsection*{}
Looking through the lists of posts for "Clipboard" I found one that seemed to be what I wanted, but it wasn't, and following the advice given (Uncheck Hide after pasting) didn't work.