Ongoing issue for over a year now…
OPEN WORLD - The Battle Standard of Coordination despawns well before its full 15 minute duration.
RAIDS - In MC, I pulled Lucifron and Magmadar together, placed the standard, then killed them both simultaneously. The standard despawned as soon as one of them gave credit, so the other did not benefit from the battle standard’s boost:
[07:05 AM] Reputation with Hydraxian Waterlords increased by 115.
[07:05 AM] You are now saved to this instance
[07:05 AM] Reputation with Hydraxian Waterlords increased by 100.