The weird thing is, before you tell me to check my support application, is that the same form comes through with all data into my support app when I use the GUI version of the form instead of the dynamically created one.
Yes.
Is it something to do with MIME_BOUNDRY or how the email is put together when called by the dynamic version?
The handling and processing of dynamic & configured forms is identical, there is only one code for both. All that changes is the point of reference, for dynamic, the GUI configured fields of a form are dropped.
Does it matter or change anything with or without Ajax support?
Can you turn off Ajax support for your GUI form and see if it still works?
How do you route the email to both your gmail account and the app?
I assum you're using the SMTP feature?
Are both forms & admin settings configured identical?
Can you try and simply use your GUI form as the dynamic one? -> nothing needs to be changed for the GUI, simply change the PHP call.