I found a very minor bug in PSoC Creator 18.104.22.1687
It may not even be a bug - what do you think?
If you have multiple files open and you select one by clickin on it's tab.
The you right click on a different tab and select 'Close all but this' then it is the selected tab that stays open, not the one you right-clicked on.
Ooops! My version 2.1 behaves differently, it closes / keeps open the tab which I right-clicked on! But this I would presume to be a questionable behaveour, I would expect either the selection changes with a right-click to indicate where the command will work on, or the command is executed for the already selected target.