On youtube.com, blocking ads results in a black screen loading for a long period of time before the video begins, nearly the length of the ad itself.
The ad blocking for YouTube is handled with an injected JS script, which is shipped with Epiphany/Web, which can be found here: https://gitlab.gnome.org/GNOME/epiphany/-/tree/master/third-party/adguard I am assuming that you are using Epiphany, and moving the issue there: https://gitlab.gnome.org/GNOME/epiphany/-/issues/2067 Please follow the issue there =)