Sometimes, I can’t drag and drop windows to other workspaces.
It always works when I just boot up my computer. After a while (most often days), it just stops working. I can’t drag and drop anymore. I have to reboot to make it work again.
I’m on Ubuntu 18.10 with GNOME Shell 3.30.2, but I remember having this problem with Ubuntu 18.04 too.
Here is a video that shows the problem: https://youtu.be/s1shbBFvt3o