The cron method was failing when calling get_record to retrieve details for a conversation record when there was more than one as get_record only expects to return a single record. This meant that any students were not added to existing conversations in a dialogue instance. Modified the method to use get_records instead and pop the first returned record. It only requires one (of a possible many) record to get the conversation fields which are common to all entries to be able to create a new entry for the additional student.