Nuget proxy 404 ? when i use nexus 3.30.1-01

2021-05-28 19:55:27,833+0800 WARN [qtp370184339-153] *UNKNOWN org.sonatype.nexus.repository.httpbridge.internal.ViewServlet - Bad request. Reason: Repository path must have another ‘/’ after initial ‘/’
39-46] *UNKNOWN com.sonatype.nexus.repository.nuget.internal.NugetFeedFetcher - Status code 404 contacting https://api.nuget.org/v3/Search?$skip=0&$top=80&searchTerm=‘log4net’&targetFramework=’’&$filter=IsLatestVersion&includePrerelease=false&semVerLevel=2.0.0