Did you know that when you reference a non existing APEX item in your SQL statements or PL/SQL code, that you are not getting a runtime error? APEX will just return NULL in such a case!
It doesn’t matter if you reference it with the bind variable- (eg :P8_TEST), V or NV function- (eg V(‘P8_TEST’) ) or substitution- (eg. &P8_TEST.) syntax.
Just be aware of this behavior!