Album search bug or syntax problem

[Zen_Master]

I'm trying to get a list of new releases of specific genres. When I filter only for "tag:new" I get results:
https://api.spotify.com/v1/search?q=tag:new&type=album

But as soon as I add one genre I get zero results:
https://api.spotify.com/v1/search?q=tag:new genre:metal&type=album

I have played around with the order of the parameters in the q-parameter and most of the times I get NULL results, sometimes I get results with mixed release dates up to 10 years or more back.
Also there is a limit of 100 results, which I can apparently override by using an offset of 100 and higher.

What I really want to do is: get all the releases from today for one or more genres (I guess I should be able to give a comma separated list of genres, right?) But the API does not have a feature for this - so I'd have to do multiple requests and even that causes problems as described above. Am I the only one who tries to do that? I would have guessed this is a common requirement.