There are a few issues i have noticed in valhalla. Sea fishing is non existent for me. An example would be whenever i fast travel into folcanstan i can see fish for about 5-10 seconds and they disappear. They never appear at all anywhere else in the coasts of england meaning i can't catch bream. Also big flatfish and big mackerel do not appear in game at all.
The eurvicscire and rygjfylke treasure hoards are missing in game for me and the oxenefordscire treasure hoard map stays in my inventory despite having collected the treasure.