I started noticing that when I looked at the Query Viewer (in the Editor), there wouldn't be any entries there after running one or more queries.
But, if I executed another query after looking at the Query Viewer, that query would show up there.
I was able to reproduce it by clicking on the data tab, closing the Editor, opening a new Editor and running a query. If you look at the QV, there will be no record of that query execution. But any that you execute after looking at QV, WILL show up.
Just opening a new tab doesn't reproduce the issue. You have to click away from QV, and open a new Editor and execute queries WITHOUT looking at QV first.