What is the bound column of the combo box? Is it expecting a number and you are giving it text?

Have you tried requering the actual controls on the form?  Are all the fields in that form in the control source of the form?
Try ControlName.requery

Are you using the correct syntax?
FieldName = Forms!FormName!FieldName

See this video: Value From a Form

Thank you for the suggestions but I've realized I had the problem completely wrong.  The On Load event is firing and my MsgBox was returning the correct value for the the default. When I realized I needed to move my SetMarkup Sub inside and If it stopped returning the value and that's when I realized that my form is not showing the correct value because the If/Then isn't working.  Form opens with the focus on the correct field and msgbox confirms the script has run.  I'm not getting the msgbox from the subroutine inside the If.  I'll upload screenshots of the code.  I've checked my spelling several times.

Try sending the ID to the Sub Routine (similar to my screenshot below).
Modify for your specific needs.

Thank you, Kevin.  I'm afraid that didn't work either.  No matter what I do the only part that works is the SetFocus and MsgBox commands.  I tried moving the entire If statement to another sub and I tried just telling it to set the combo to a fixed ID other than the default and not joy.

So I made a workaround.  Since the SetFocus was working I just moved my code to the GotFocus event of that field.  Form works perfectly now.  You got me thinking in terms of moving stuff to other places and that led to my solution.  Much obliged.