results tab = the "Text Search Query - Results Preview" tab
reference tab = the new tab opened from the results tab "Summary" or "Reference" view.
When I have made a new Text Search, and want to explore the results before saving the query, it the results tab unexpectedly disappears.
When I open one of the references (reference tab), this will often close the results tab. Not always, and I've not determined the pattern yet. I think the longer the new tab with the result is open, the more chance of the text search result tab has of closing.
When I use the find tool (ctrl+f) to look through the opened reference, this will often close the results tab. Not always, and I've not determined the pattern yet.
This happens more often, the longer I've had NVivo running.
I don't like that I loose my layout after closing and reopening NVivo (i.e the files I have open when I close NVivo are not re-opened when I re-open NVivo), so I don't close it as often as I probably should