Vivaldi does not support Bylgjan (Icelandic) player.
The players window comes up but no sound.
@LarusG Please explain. Your Thread title was so short and the post not clear enough.
The Vivaldi forum has no bug as it uses not such player.
May be you posted the wrong forum.
Or do you want to say, that Vivaldi does not have a sound at http://vefutvarp.visir.is/player#/bylgjan