Firefox Community Forum

I'm trying to find a solution for having all tabs open across devices. Currently, my desktop has about 50 open tabs that I access regularly. Today, I installed Firefox on my laptop, signed in and initiated syncing. All bookmarks came over, everything looks great, except that none of my open tabs from the desktop browser show on my laptop.

I would like to have identical tabs open across devices. Is there a way to configure this where a new computer being logged in automatically receives all open tabs from the initial device and then tabs automatically sync based on whatever is opened/closed on either device after the initial tabs are identically synced?

I search but did not find any list of environment variables supported by Firefox. Is there such an official list, perhaps groupped by Firefox version, published somewhere?

Home Internet speed via cable 500 Mbps. When checking the Internet speed through the Firefox browser (version 133.0.3), incoming and outgoing about 250 Mbps. That is, the browser cuts the speed twice. When checking the speed through Google Chrome (version 145.0.7632.160), the Internet speed is about the declared 500 Mbps. Please help solve the problem with Internet speed through the Firefox browser.