Problem at certain zooming levels (missing tiles)

Hello I have problems at certain zoom levels. I searched a little bit but I didnt found anything similar. Is the problem on my site or is it a known issue?
I’m using Opera 47.0 on Windows 10

I attached a screenshot of the problem. The city I wanted to discover was Nuuk, Greenland

Thank you for helping.

Stormregion0

I don’t think that the German style tiles at https://a.tile.openstreetmap.de/tiles/osmde are generated for the whole world (I’ve certainly seen other places where they only go up to z17). Whether that’s by accident or design I don’t know - ask someone who’s in charge of that server (the DE forum here would be a good place to ask).