Since latest update (Gnome 40) the "dash to dock" shows no more window previews

[screwtape]

Take look in the last Stable-Update-Thread:

[Stable Update] 2021-07-13 - Kernels, Plasma 5.22, Cinnamon 5, Gnome 40, LibreOffice, Mesa, Nvidia, Pamac

I cannot open Dash to Dock settings, and the dock looks ugly (see below). Dash to Dock is not supporting Gnome 40 yet. You could try to install AUR (en) - gnome-shell-extension-dash-to-dock-gnome40-git