Time: 8:42PM EST
Frequency: All the time (Frequent)
World name: Cactuar
Character name: Emmeryn Rosehilt
Monster name: Bismarck (Ex)
Class/Level: WHM 60
Party or solo: Party
In-game time: Not sure
Area and coordinates: The Limitless Blue (Extreme)

Steps:
1. Queue into the Trial Bismarck Ex
2. Destroy the Carapace and get to the 2nd phase of the Trial
3. Look at Timers of the Wind/Water Debuffs
4. Counting down from the the "Brace Yourselves" message (DPS check), look at the duration of your debuffs
5. On the third debuff application, you will notice that the phase ends even though the Debuff still has time left on it (This varies, from 25s to 40s)
6. Rinse Repeat.

Additional comments: Our DPS was up to par to manage to finish the phase with its standard 130s timer, however with this bug we found ourselves to only have 90s on average to attempt to clear it which would be impossible even if we used any type of Limit Break 1 during the phase.