About 1 month ago , when starting Firefox it opens in ALL windows. I usually have about 4-5 widows open and flick between them. Irritating, FF is in the foreground and covers whatever is open. I was hoping it would fix itself with new versions but it is not happening. Safari starts in one window. I want Firefox open in just one window, like it used to be. How can I get it back? Have the most recent upgrades of macOS and Firefox.