No its not. That should still work.
In fact the query editor has been enhanced with a new Add Tables dialog which you may find easier than dragging tables
Out of interest, are you using a Windows tablet? I ask as I've had some issues with using Access 365 on my tablet recently
No tablet, it's a Win 10 desktop. I suspect it was a temporary artifact from a poor quality connection to the Internet. I left the editor open, did other stuff a few hours and when I went back to that it worked normally.