@sajarac
If your total is coming only after form 2 is submitted and yet you have already submitted form1, then you will need to make another data operation in your form2 to update the record you make/updated in form1.
My suggestion would be...
Change your submit to be only: SubmitForm(Form1)
In Form1 in the OnSuccess Action, set the formula to:
Set(glbCurrentRecord, Self.LastSubmit); SubmitForm(Form2)
In Form2 in the OnSuccess Action, set the formula to:
UpdateIf(yourForm1DataSource, ID=glbCurrentRecord.ID, {TotalColumnName: <totalColumnValue>})
I hope this is helpful for you.