Starting release of Firefox 127.0 the “browser.privateWindowSeparation.enabled” preference stopped working (I believe it was removed in the commit here: https://phabricator.services.mozilla.com/rMOZILLACENTRAL8adde2b08299cbe12d25785fcb0efdabb0057766) and now Firefox private and normal windows have their separate icon in the Windows taskbar. Could you restore that functionality? If not by bringing back the “browser.privateWindowSeparation.enabled” preference on the about:config page, then e.g. add a new setting on the Firefox settings page that does the same thing.