No superevent was created for G555966
While investigating an anomaly seen in GraceLive (in Mattermost thread https://chat.ligo.org/ligo/pl/c6wy5ijiijfn5eino9nkhmkqyy), I discovered that G555966 has no superevent. It SHOULD have a superevent; it is a CWB event with FAR 1.3e-05 Hz. Compare with the very similar CWB event G555974, for instance, which was generated about half an hour later and has slightly higher FAR.
Can gwcelery experts check logs to see if gwcelery received information on G555966 from GraceDB, or if there is any indication of a problem?
One hypothesis here is that some igwn-alert messages are getting lost occasionally. GraceLive seems not to have received the "new" igwn-alert messages for three CWB G events in a span of 35 minutes: G555963, G555966, and G555974. The first and third of those have superevents, so gwcelery must have received igwn-alert messages for those. The middle one, G555966, is the only one which seems to have been missed both by gwcelery and by GraceLive.
Following up: I checked all the G events in a ~31 hour time span, from G555095 (2-20 9:50 UTC) to G556231 (2-21 16:46 UTC). In that time span, G555966 is the ONLY G event which should have a superevent but doesn't.
