jenkins Nexus Artifact Uploader 400
As mentioned in "400 BAD request HTTP error code meaning?", an error 400 means the request was malformed.
In your case, a possible cause is the GAV you want to send: the Version is 1.0-SNAPSHOT... sent to a release repo: that kind of version would be rejected by Nexus.
That "Repository policy" should be "snapshots" in order to accept 1.0-SNAPSHOT.