The NRPE check removes the temporary output file created by the collector cronjob, which introduces a race condition that will make the check fail if the file is not present. While the commit where the check was added (faefe90ce6beb5d2b3721cfb637dd7d661cbc21f) mentions that the file is removed so that the check will always have fresh data, it can fail and has been failing on an environment for 10+ hours straight. I think having minute-old stale data is better than having no data at all and having the check fail, so I believe that removing the section of the check that removes the output file [0] would fix the issue, as the collector CRON job already handles the output file being present by using the write+truncate mode on the open operation [1].
[0] https://opendev.org/openstack/charm-ceph-osd/src/branch/master/files/nagios/check_ceph_osd_services.py#L41-L45
[1] https://opendev.org/openstack/charm-ceph-osd/src/branch/master/files/nagios/collect_ceph_osd_services.py#L72
Agreed that the race this could create can lead to false positives which causes alert fatigue and ultimately can render a check useless (although I can't help but wonder if there's an underlying env issue if it's failing in an env for hours on end as a side note).