Tabs sharing over local network even though Sync is disabled

Hello, I have multiple devices using Firefox on the same network, and whenever using them at the same time, I get an additional Firefox icon in my doc which will open wha… (ketahui selanjutnya)

Hello, I have multiple devices using Firefox on the same network, and whenever using them at the same time, I get an additional Firefox icon in my doc which will open whatever tab is up on the other device. I was not signed in to any account on either device, yet it is still sharing tab data across devices.

I then created an account and signed in on one device and disabled every Sync option I could find, but still the sharing is enabled over local network. How do I disable this so there is no communication between the two devices?

Device 1 - MacBook Pro (Retina, 13-inch, Early 2015) macOS Monterey 12.7.6 Firefox Version 149.0.2

Device 2 - MacBook Pro 14-inch, 2023 macOS Sequoia 15.4.1 Firefox Version 149.0.2 Local Network access disabled for Firefox in macOS settings

It doesn't seem like this should even be possible given that local network access is disabled for the one device, and neither device is logged into a mozilla account.

Can someone please help me disable this functionality?

Open