@gbjack thank you ! Default adblock lists in Vivaldi caused in a French Canadian news website a popup to disable ads blocker (EasyList cause it). With some tests, I've been able to hide this popup and ads in the page, but big rectangular spaces took too much space on the page. With your link and lists suggested, all working great now on that website. No ads and big blank spaces are hidden.
With Brave Browser, default embedded ads blocker work fine without any changes.