The question is not Popup_Upload, but OnNotify.
I will explain it in another way. I have a screen with a TEMP variable and a link to a popup. I open the popup and when I close it I run OnNotify which updates the TEMP variable, but it keeps the original value, that is, I can't change it.
Step 1: Variable TEMP = "TEST"
Step 2: Open Popup (here no matter what happens)
Step 3: Close Popup
Step 4: OnNotify runs
Step 5: Assign TEMP = "TEST_1"
Step 6: Click OK button
Step 7: TEMP display "TEST"
TEMP contains value "TEST" and should contain TEST_1
Why Assign TEMP = "TEST_1" didn't change the variable's value within OnNotify?
On the other hand, if I change the TEMP value within Action "OK" the value remains, it does not work when OnNotify is run when closing the popup.
If necessary I create an application to send to you
Screens:

