Starting R12.51 the WebAgent code assume Localization=YES by default, if it is not set within the ACO. Hence if it is not defined in ACO, then it is YES by default and WebAgent would load localized pages i.e. /forms_en-US/smpwservices_en-US.fcc
If we need WebAgent to load customized OR non localized fcc pages, then we need to add a ACO parameter explicitly and set it to NO. This will ensure WebAgent loads /forms/smpwservices.fcc
Check webagent trace log to verify which FCC page is called.