Forms :: Successfully Updating A Combobox Not In List Event

I have a basic form linked with a subform inside of it. The main form has a list of customers in a combobox and the subform lists all the things they have ordered from us. This all works perfectly fine, I can add data to the list of things ordered and it's ok.

I decided instead of using a whole extra form to add customers I'd just have a not in list event and allow users to add customers through there, bit more intuitive and cut down on forms.

It works to certain extent except one small problem, if I add a customer I have to close and reopen the form to be able to add/remove data from them in the subform. If I leave the form open and try to enter in data in the subform immediately it just shows whatever customer I had last on the combobox and adds it to the last customer as well.

It works perfectly fine if I reopen it so I thought it was some kind of query or update snafu but all the VBA code examples I found don't seem to do anything. Not exactly sure where to go from here.

PHP Code:

Private Sub cboDept_NotInList(NewData As String, Response As Integer)
    Dim oRS As DAO.Recordset, i As Integer, sMsg As String
    Dim oRSClone As DAO.Recordset
    Response = acDataErrContinue
    If MsgBox("Add dept?", vbYesNo) = vbYes Then
        Set oRS = CurrentDb.OpenRecordset("tblDepartments", dbOpenDynaset)

[Code] .....