Unable to Obtain Selected Rows of an AB in Event Handler

Hello All,

    We are unable to obtain the indexes of selected rows in an event handler(a button on the assignment block) using the following code-:

    lt_bol_index_tab = me->typed_context->ztabxyz->collection_wrapper->if_bol_bo_col_multi_sel~get_marked_indices( ) .

    During debugging it was found that in the method DO_HANDLE_DATA , the collection has all the entries with the selected ones marked , while on the       event handler the same collection is reduced to one entry with initial values.

    After the event's execution, the method DO_PREPARE_OUTPUT again displays all the entries in the collection, only none of them are marked this            time.

    Please help us find out the issue here.

    Further Information-:

        The selection type is Multiselect in the .htm as well as do_init_context.

         The method ON_SELECT is not invoked as a flag has been set in standard coding that sets the marked entries on a server event other than row selection( hence we are able to obtain the marked data in do_handle_data ).