Firefox won't go into background on Windows 11

Hi, I'm on Firefox 147.0.3 and windows 11 business 25H2 (26200.7623), with two displays. For the past few weeks: - firefox stays on top - alt-tab to other window on that screen doesn't work, other app is not displayed over firefox - clicking on other app icon in task bar doesn't bring it to foreground/top - even other firefox window (like new private window) is opened in background - the only way around is to minimize firefox - without firefox opened, everything works normally It is really disturbing my flow / ways of interacting with apps / habit of using keyboard to move between apps. Is it a bug, or is it a matter of some settings? I've seen similar quesiton from 9 years ago https://support.mozilla.org/en-US/questions/1140245 but there is no setting of the same name now?