Using a number of different Apex versions - on this particular server it is Apex v4.0.2
The documentation for JavaScript APIs indicates apex.submit() as setting the REQUEST variable - which I assume is the standard request item value used in Apex.
I have debugged the submission on the browser side and apex.submit() does POST the request value (as variable p_request). But the value is not accepted or set on the server side. Using :REQUEST or v('REQUEST) in the page's regions does not show the posted request value. It is null. There is no explicit branch condition on the page.
What do work is that the page items assigned values are submitted and seen by the back-end. E.g. if P1_NAME is set in apex.submit(), that value is seen via page regions/processes after submission. Unlike the request value.
Am I doing something wrong? Is this an issue with an older Apex version?