
I have the same problem, which appears to be a huge security flaw on recent Mac operating systems running Firefox. (For the record) Posted by '''agarratt''' in another thread: Read this answer in context 👍 0 All Replies (1) Pick up where you left off with Handoff on Mac - Apple Support

Mac Book shows icon "Firefox from iPad Air" in the Dock on the left side, how to remove

Here’s the scary part: when I click on the Firefox icon with the TV screen the web page open on the other Mac computer, or iPhone, shows up on my MacBook Pro, replacing my Firefox screen. This time when I rolled over the icon it said “Firefox from iPhone.” When I turn off Firefox on the iPhone, the icon goes away. Then I checked and turned on Firefox on my iPhone and the Firefox icon with the tv appeared again. When she turns it off, the icon goes away. When my wife turns on her computer (running Mojave) with Firefox, I get the extra icon. I noticed the Firefox icon with the tv screen after I started running Monterey (I had been running Mojave).

(For the record) Posted by agarratt in another thread:
