How to set regularly use of "et al." to Nature citation

Hello there, i would like to know how i can change the "Nature" CSL bibliography so that it writes et al. always after the first name. Right now I have the Problem, that my bibliography is very inhomogenous, sometimes there is an "et al" sometimes it writes 4 names. I already tried to change the CSL settings of author:Name:et-al-use-last to "true" and "et-al-min = 1" as well as "et-al-first = 1". If I do that, there are absolutly NO et al.s in my bibliography at all. Would be great if you could help me.