You can use sync to share passwords, bookmarks, and history. Anything else may not be compatible between different browser versions or computer systems.

https://support.mozilla.org/en-US/kb/how-do-i-set-sync-my-computer Sync your bookmarks, history, passwords, add-ons and open tabs with another copy of Firefox. Learn how to set up Sync.

https://support.mozilla.org/en-US/kb/how-do-i-choose-what-types-information-sync-firefox We'll show you how to choose which types of information (bookmarks, history, add-ons, and passwords) to share across all your devices through Firefox Sync.

https://support.mozilla.org/en-US/kb/firefox-sync-troubleshooting-and-tips

https://support.mozilla.org/en-US/kb/sync-firefox-bookmarks-and-browsing-history-iOS Sync your passwords, history, tabs and other browsing information across your iOS, Android and desktop computers with Firefox Accounts.

You merely need to sign in to the same Firefox account (email) on each device.

Thanks to both FredMcD and cor-el, but I am logged into the same firefox account on both laptops and sync is on, but literally nothing is getting shared and without my tabs being preserved, there is no point in syncing at all.

Do the following on each member of the sync. Lable each as to what computer/profile it is.

We need to look at the sync logs.

Note: Do the following for each problem system/profile. And label each as to what system/profile.

Type about:sync-log<enter> in the address bar.

Open the last file created and Copy its contents Now Paste it into this forum.

If the file is too large;

Have your web browser go to; https://pastebin.com/

Paste <Control> P the content of the file in the window. Note: On the bottom, fill out the boxes as best you can.

Now press Create A New Paste. The page will reload. Copy the new web address, and post it here.