No problems with the inbuild adblocker in Vivaldi, not even in YouTube (without any ads for me), problems only for Chromiums in which are remaining control and tracking APIs from Google and which are only can use "descaffeinated" Adblockers from the Chrome Store. I can use even direct userscripts in Vivaldi if needed, without the need of Tamper-, Greasy- or Violentmonkey extensions.
Vivaldi is a Chromium browser, but Google for the past 9 years has hit its teeth on a rock in attempts to control it.