Window #1 (TOP) is the primary (1st) window.
Window #2 (Bottom) is the secondary window.

When activating Window#2, pressing Ctrl+F||Ctrl+H opens a dialog (briefly) then it seems to go off the desktop – disappears.

When activating Window#1, pressing Ctrl+F||Ctrl+H opens the Search/Replace dialog.

After opening the Search replace dialog, I click on the 2nd window (bottom), then the Search Dialog – attempt a search.

The search is performed from the primary window – I assume since that is the window that opened the Search/Replace dialog?

Except the search should be performed in the 2nd (bottom) window – as it was the last active window before switching to the search/replace dialog.

Thus as it stands now, am unable to do search/replace from the Search Dialog in secondary windows — aside from using the inline Search-Toolbar.