NOT filter doesn't work

I used the following filter @filter(Not eq(Branch.name, "master") in the query so now the whole solution looks like this:

 var(func: uid($repoId)){
      Repository.branches @filter(NOT eq(Branch.name, "master")) {
      Branch.versions {
        N as Version.number
      }
      LV as max(val(N))
    }
 }

repo_branches(func: uid($repoId), first: 7) @normalize {
      Repository.branches(orderdesc: Branch.last_updated, orderasc: Branch.name) @filter(Not eq(Branch.name, "master")){
     branch_name:  Branch.name
      Branch.versions @filter(eq(Version.number, val(LV))) {
        latest_version: Version.number
      }
    }
  }

What do you think