Setter method not working after EnhP 7.1

I want to put a default value on BT125H_TASK/TaskDetails view in OBJKEYA field. So I have written the following code in do_prepare_output. This code was working before we have upgraded from 7.0 to Enhp 7.1. After upgrade this code is not working. I have debugged the code and lv_value is being calculated properly, the debugger is going inside set_objkeya method, but at the end not setting the value in the field.

IF lv_ptype = 'ZYUR' AND lv_value IS NOT INITIAL.

me->typed_context->btdocflow->set_objtypea( attribute_path = 'OBJTYPEA'

value = 'OPPORTUNIT' ).

me->typed_context->btdocflow->set_objkeya( attribute_path = 'OBJKEYA'

value = lv_value ).

lr_core->modify( ).

ENDIF.

Please suggest.