Page Process not executing no matter what condition I use (or no condition at all)

Hello.

I am trying to execute a page process AFTER SUBMIT named UPDATE_INV_TOTAL_INITIAL that is used to compute an invoice total and update that total into Oracle APEX table:

<code>

update invoice
set inv_total = 0

where inv_id = :P310_INV_ID;

</code>

It doesnt matter what order the process is, if it is conditional, or not.  APEX does not execute it.  Why would that be?

The 'Unconditional' Process Row of Invoice works fine and is executed before the page process UPDATE_INV_TOTAL_INITIAL.

Thanks in advance for your help!