I watched the 3rd episode of Apo. There was one sentence that triggered me hard, namely:
"I am the travelling knight from the Netherlands, Siegfried."
No Siegfried, you are not from the Netherlands. According to the Nibelungenlied you from Xanten, which is in the lower rhine region.
...this is a setting where King Arthur and Mordred are women, why are you surprised by other things being inaccurate/wrong?
The Nibelungenlied states he's from the Netherlands. It's right in Siegfried's introduction.
In the Netherlands there grew the child of a noble king (his father had for name Siegemund, (1) his mother Siegelind), (2) in a mighty castle, known far and wide, in the lowlands of the Rhine: Xanten, (3) men called it.
He's repeatedly referred to as being the hero of the Netherlands in the poem.
Apocrypha did not invent that.