I believe Der Speigel has a pro-SPD bias (German commentators, please fact check this for me - my Deutsch is a bit weak), and the SPD is a member of the same European Parliament coalition that is in the middle of Qatargate [0][1]. There is an interesting article in Politico EU about the Qatar-Germany nexus [2], but it should be noted that Axel Springer, the owner of Politico EU does have an anti-SPD bias which may play a role as well, but I am not sure if this bias has rubbed into Politico EU.

[0] - https://en.m.wikipedia.org/wiki/Social_Democratic_Party_of_G...

[1] - https://en.m.wikipedia.org/wiki/Progressive_Alliance_of_Soci...

[2] - https://www.politico.eu/article/qatars-germany-sigmar-gabrie...