Not sure if this is a bug or functionality but when I set up my number formatting in fields view in Pro and then publish to AGOL that formatting does not carryover. I end up having to go back through configure attributes and manually change the formatting for everything. Not only is the table wrong but pop-ups are also reset. Like I said, maybe it's a bug.
Another thing that does not carryover are suffixes. Why have it in Pro but not have the ability to publish to AGOL and have those carryover? Seems pointless especially if I have to make arcade expressions to mimic what I have in Pro.
One last thing that I found interesting is when I publish to AGOL it puts thousands separators in everything. Even if I did not designate thousands separators in Pro. I'm running Pro 2.3.1 by the way.