Time: Around 8:00 PM PST
Frequency: Very rarely
World name: Coeurl
Character name: Yenn Sylph
Monster name: Titan
Class/Level: 50 Summoner
Party or solo: Party
Steps:
1. Cast Aetherflow as part of a regular SMN DPS rotation.
2. Notice that very rarely, it will go on cooldown without restoring MP or applying Aetherdam.

If anyone has additional information on how to reproduce this, it would be appreciated. It get this very rarely (maybe once for every 4-5 hours of combat), and seems to be related to using abilities at the same time.
I can't figure out exactly how to reproduce it, but it definitely happens.