What could be the reason that I am not able to see these metrics for my instance?

logstash_stats_events_in
logstash_stats_events_out
and
logstash_stats_process_cpu_load_average_1m/5m/15m

However, I am able to correctly see:
logstash_stats_pipeline_events_in
logstash_stats_pipeline_events_out

Any suggestions please?