Refresh Custom Ribbon not working

[cNorth]

Hi,

I am trying to share some macros created in Word with my colleagues. I have created a custom tab and added macro buttons to the Ribbon and they run as required for me. However, when I share the file /ask colleagues to save it to the Startup folder, they are unable to see the custom ribbon tab. If they select the Developer tab, and then the Word Add-ins command, the file is listed under the 'Global templates and add-ins' section but the check box is unchecked. When they select the checkbox manually, the custom tab appears. I think the issue is to do with the ribbon not refreshing, if anyone can offer any tips I'd be really grateful.
I have this in my module

Sub RibbonOnLoad(ribbon As IRibbonUI)
Set myRibbon = ribbon
End Sub

Sub RefreshRibbon()
     
On Error GoTo RestartWord
  myRibbon.Invalidate
On Error GoTo 0
 
Exit Sub
 
RestartWord:
  MsgBox "Please restart Word for Ribbon UI changes to take effect", _
    vbCritical, "Ribbon UI Refresh Failed"

End Sub

Thanks