Just being a 'user' , this is simply to report (and hopefully get it all working again) to the greater good on here and at Mozilla, that popup/ephemeral windows , or whatever they are called, in the 115esr release no longer function correctly (they did with the previous versions) with TWM window manager in this experience. When clicking on a tool bar icon that launches a 'popup' type window, or in forms using 'drop down' controls for example, as soon as mouse moves over the popup or the popup gets focus, the popup gets closed immediately; it does not stay around to enough to allow a selection or whatever, as it should. If one can 'tab' into a popup and use the keyboard (keyboard focus so to speak), then it is possible to access some options. The keyboard focus does not seem to cause an immediate close like the mouse does (as above). As an aside, Chromium suffers the same now It is something mouse related it seems and with how it all works with TWM - which is old, but as said, there was not a problem previously so whats changed in this version of Firefox browser to introduce this 'bug'. Peace and best wishes to all Habs