VBA Project File Sharing and Project Check Out

Question

Sorry, I'm not sure whether I'm at the right place for asking this question, but I'm turning around anf around to find an answer to this simple question:

1. I got my project file from Project Server
2. I export the project using the save for sharing method
3. I try to save it to the project server back
4. Got an error message telling me the project is already checked out (to my name)
5. I actually see the project being checked out when the FileOpenEx statement is executed

      ' Ouvre le projet qui est sur le serveur
       prjApp.FileOpenEx Name:="<>\Médias sociaux", ReadOnly:=False
   
       Set openProjects = prjApp.Projects
   
       For Each proj In openProjects
           If proj.Name = "Médias sociaux" Then
               If Not proj.Type = pjProjectTypeEnterpriseCheckedOut Then
                   proj.CheckoutProject
               End If
               If proj.Type = pjProjectTypeEnterpriseCheckedOut Then
   
                   ' Le projet a été verrouillé, sauvegarde locale pour manipulation des chiffres
                   tempFolder = objFileSystem.GetSpecialFolder(2)
                   prjApp.SaveForSharing Filename:=tempFolder & "\" & proj.Name
                   fait = 0
   
                   ' Sauve le fichier et le publie
                   prjApp.FileSaveAs Name:="<>\Médias sociaux", FormatID:="MSProject.mpp"
                   prjApp.FileCloseEx pjDoNotSave, True, True
   
               End If
           End If
       Next proj