Reading your post, it would seem your issue is Multiplayer has gone missing, not Real-Time Online Traffic.
The former is your connection with real human players and the latter is traffic represented by actual aircraft traffic.
You may wish to alter the title of your thread to see if it snares other posts that might solve your issue.
That said, you need to examine the Multiplayer aspects of the sim and not the traffic aspects.
Check that you are all on the same server and check that multiplayer is turned on.
I’d also do a search here in the forums for related issues. I recall reading something in the past where people had lost the ability to connect with their friends, but I don’t recall the solutions.
Additionally, I don’t know how the cloud version of the sim works with all this, as I’ve not utilized it, however I do run the sim on a Series X.