iCloud tabs not syncing/working

I know it sure is frustrating. If you call Apple, it is free to talk with an advisor. I worked with a senior advisor, told them the steps I already did. We ran through some more steps and I ended up having to send my diagnostics to their engineers. It took a few days (the engineers work via email only), but they did get mine working. With that being said it took a lot of time and caused heaps of frustration. I made two appointments Apple certified repair locations and they both said it had to do with Apple iCloud servers. So I don’t think you can do anything to fix it, if you already ran through the steps. I think they have to fix it at their end. I had three Apple devices not working. They asked me to clear my device and start again. I refused to do that because there was no way three devices were not working correctly. Also, one of my devices was brand new. I also had an Apple location removed the newest iOS I just put on and replace again, just to see if they could fix it. They could not help me. I’m just trying to save you some time. This is what finally ended up working for me. I hope this helps.