Admob Ads not showing - no fill from adserver

I have a brand new admob account which I´m using in my appp, and the Logcat output says there is no fill from adserver since over one week.

A friend of mine has the same problem with his account.

Both are veryfied with my and his mobile number.

Currently I have about 450 ad requests a day, which is not too less and that´s why I don´t understand why there is no ad showing up.

I think Admob has changed something for new accounts, so when do I get ads served? Do I need a certain amount of play store downloads first or is there just a delay of two weeks or similar?

Did you find any solution? I am also getting the same response “no fill” from the server. I am using latest admob from google play sdk.

I have very very low fill rate of 6-7% for newly created banner ad units in new admob.