I think I've figured out the problem. As I have no cards from Shadows over Innistrad, I've outconfigured the Innistrad block completely. It seems like the legality settings take those configurations into account and because my copy is from AD&D Commander, it is regarded only as Commander legal. In my opinion the legality should be unaffected by block configurations and stay constant.

I've found out that the card was originally printed in Shadows over Innistrad and therefore is Pioneer and Modern legal. But as the complete Shadows over Innistrad edition is missing atm, the card (which is from Commander AD&D) is not linked to the SOI one. Therefore it is only regarded as Commander legal.

Like this? https://www.urzagatherer.app/?card=67178

I am on 7.16.3. In my client it is still wrong (not legal in Pioneer, Modern). Do I have to clean some cache or so? Its the same with the android app, if that is important.