I had the same issue so I switched to workaround to dynamically fill dropdowns, here is an example:
detailDropdown("Specialization", "spec", "pri", 1, 40,
false, "", "$args.spec",
"no", "spec", "$args.spec",
"","","no","","",
"$args.spec",
<PDM_LIST prefix=list where="delete_flag = 0" factory="z_spec_list">
"$list.value", "$list.id",
</PDM_LIST>
"Default", "0"
);
Regards,
Timur Alimov