Something has changed between FF 80.0 and 80.0.1! Aug 30 and Sept 03, 2020. Either a change to the code for uBlock Origin, or a change Yahoo made, that doesn't like uBlock now.
On Aug 30, 2020 I could access my contacts normally in Yahoo mail. Now on Sept 03, My contact list is grayed out, until I turn off uBlock, then my contact list appears normally! I STRONGLY suspect yahoo made changes, since the uBlock update preceded this problem!
It may also have to be Off to allow display some web flyers!

Guter Schutz vor dauernder Werbung

En matière de blocage de pubs, il est une référence. On peut y apporter nos propres listes, ajouter des règles dans les filtres, le filtrage dynamique.
Une excellente extension.

I miss the old version where you could actually control what does and doesn't get to load.

Bloquea sonidos y audios de páginas web

ublock origin block some parts of ebay, for example Purchase history, even if it can be solved with the advanced options.

perfect