In one clip, Neumaier was seen singing the Nazi-era German national anthem...

I find this more disturbing

It’s still the German anthem, it’s not especially Nazi.

Are you saying the modern German anthem is the same as the Nazi era German anthem?

More or less. The Deutschlandlied) is the hymn of Germany since before the Nazi era, wasn’t changed by the Nazis and still is today. But today only the third stanza is officially the hymn. However, people often sing the first one, which is the most well known.

However, people often sing the first one

Correction: Nazis - and only nazis - often singe the first one.

Are you sure? I may be wrong, it wouldn’t be the first time, but I have the impression that people sing easily “Deutschland über alles”.

(For context, I never lived in Germany, but always near the border, so I have sometimes a distorted vision of what occurs there)