Another run today:
https://uberchromeos-server38.corp.google.com/new_tko/#tab_id=test_detail_view&object_id=579776220

Kefka:
https://uberchromeos-server38.corp.google.com/new_tko/#tab_id=test_detail_view&object_id=582674855

M62-STABLE-CHROMEOS-1 (9901.54.0, 62.0.3202.74), (9901.54.1, 62.0.3202.74):
https://cros-goldeneye.corp.google.com/chromeos/console/viewRelease?releaseName=M62-STABLE-CHROMEOS-1

samus (failed to reconnect after rebooting before any update started) / chromeos2-row3-rack10-host5:
https://uberchromeos-server38.corp.google.com/new_tko/#tab_id=test_detail_view&object_id=583275457

daisy (lost connection while copying stateful) / chromeos2-row4-rack8-host22:
https://uberchromeos-server38.corp.google.com/new_tko/#tab_id=test_detail_view&object_id=583198560

cave (lost connection while copying payloads) / chromeos2-row8-rack7-host13:
https://uberchromeos-server38.corp.google.com/new_tko/#tab_id=test_detail_view&object_id=583303063

eve (reboot after update) / chromeos2-row8-rack1-host16:
https://uberchromeos-server38.corp.google.com/new_tko/#tab_id=test_detail_view&object_id=584535824

This has been happening a lot in this week on the CQ.
See for example, issue 768542 and issue 777920

As noted on those issues, this particular symptom can result from a lot of reasons, and you need to look at the following repair job and dig deeper to figure out what is happening.
So, realistically, this bug will only get attention when you have those details here, specially because given the various boards above, my gut feeling is that you're talking about 4 different failure modes here.