When editing in a SQL Query Tool tab:
pressing the mouse left side/back button hides the content of the tab and controls:
This also impacts other tabs spawned from that tab using the "new query tool for current connection" control.
Child tabs are impacted in reverse order of spawning. A tab that has "child" tabs will not get hidden by the first click but will take as many clicks to be impacted as there are open child tabs. Each child tab is hidden in reverse order of when it was spawned.
following that with pressing the right/forward mouse button sometimes brings back the text as it was entered, but sometimes clears the contents of the tab.