[Designer Cannot scroll layers panel by dragging]

This happened to me too. And it also affects the brush menu and you cant scroll it. I havent tried it yet because of the hassle but i think you might have to reset the whole application to the state it was when you first downloaded it. If someone has the pleasure to do this, do it, and tell me if it worked.

however here are some workarounds. If you cant scroll the brushes just add enough brushes in that category until you get the scroll wheel to show up. Then you can use the wheel again to scroll. You may also scroll down the layers manually using the scroll wheel.

personally i think the issue resides somewhere with how affinity views its studios. For example before this stopped working i think affinity recognized that the windows were sectioned off by each other, in my case the layers and the brushes, and that the space between them should be treated as its own. Thats why it scrolled then. Now i think affinity thinks each of these windows are their full extent, because for example if i pull down the layers to reveal the full brush set theres not enough brushes to go outside the screen and thus make the scroll wheel turn up. I think affinity now view both the brushes and the layers as two fully enlarged windows.