Similar to this post: https://support.mozilla.org/en-US/questions/1417523 This issue is only on two computers (24" iMac running Sonoma) - others at the client site work normally. Client has up to date Firefox (127.0.2 - also tried latest ESR) full screen with multiple tabs - config set to use system print dialog by default. Print - print dialog opens, print is sent. Tabs are now greyed out, cannot type in text boxes. Changing context (opening and closing About Firefox) restores normal function. set up a new profile - same issue. Any suggestions?