Nuget package publish is publishing lower versions intermittently

I am trying to publish Nugets to my Nuget server that are to be used in my application. But when I see the version that it's publishing, sometimes it's lower than the latest version on the server because of which the update is not visible in Packages Console Updates tab. This is happening intermittently. Any ideas why will be appreciated.

We use CLI to publish the packages and below are the steps. 1. cd .<project_name> 2. ...nuget\NuGet.exe pack -Build -Prop Configuration=Release -IncludeReferencedProjects 3. ...nuget\nuget.exe push .nupkg -SkipDuplicate -source http:/***** 4. del *.nupkg