Power App ComboBox not defaulting to selected option when going back to screen

[TesDA]

I have a combox field in a form that should return to what was selected when a user goes back to the page from a page further on:

Screen - scrForm1

Card: ProjDir_DataCard2

-Sends data to App_PAFNewProj_Main sql table in sql server

ComboBox: ProjDir_ComboBox

Items - Sort(Filter(EmployeeData, DirectorFilter = "Director"), 'Employee Name')

SelectMultiple - False

Default - blank

DefaultSelectedItems -

If(varFormMode = "edit",
   {ID: LookUp(App_PAFNewProj_Main, ID=varRecord.ID), Value: Gallery_Main.Selected.ProjDirName},
   If(varBackScr2 = "back",
      LookUp(App_PAFNewProj_Main,ID = varRecord.ID),
      Blank()))

Use the gallery if the person is coming from the gallery, if they are using the back button do a lookup. The lookup is what is not working

When the form is submitted:

Set(varRecord,Form1.LastSubmit);Navigate(scrForm2_EQRAttach,ScreenTransition.None)

Screen 2: scrForm2_EQRAttach

BackButton - Icon7

OnSelect - Set(varBackScr1, "back"); Set(varBackScr2, "back"); ResetForm(Form1); Navigate(scrForm1, ScreenTransition.Fade)

[RandyHayes · Accepted solution]

@TesDA 

Yes, your DSI (Default Selected Items) property will never match the Items records...

Your DSI property should be: 

Coalesce(Parent.Default, Gallery_Main.Selected.ProjDirName)

I hope this is helpful for you.