In V7, where the java execution engine became the default, logstash does not preserve the order of lines in the file, even with '--pipeline.workers 1'. Thus the end is processed before the begin, so you get a "elapsed_end_without_start" tag.
For now you could set 'pipeline.java_execution: false' in logstash.yml, but I do not expect elastic to maintain two engines, eventually java will be the only option.