Date & Time: 9/12, 1:40pm CST
Frequency: Happened twice, two different fishing windows
World name: Diabolos
Character name: Honorine Elouan
Monster name: Charibenet (big fish, int triggered with 5 ice pixies)
Class/Level: FSH/100
Party or solo: Solo
In-game time: Between 0-3 am
Area and coordinates: Coerthas West, X 36.5, Y 6.3, Z 0.7
Steps:
1. Caught 3 HQ ice pixies, saved as swim bait.
2. Caught NQ abalathian smelt and released it.
3. Caught 1 NQ ice pixie.
4. Caught 1 HQ ice pixie, triggering fishers intuition with the 5th. "It smells of a rat..." Used mooch and caught a Hotrod.
5. With fishers intuition and makeshift bait both active, caught 1 HQ ice pixie, refreshing fishers intuition. Received "The reek intensifies!" message.
6. But then, the ice pixie I just caught was released without me Releasing it. When I go to the release list, HQ pixies are now on there along with NQ/HQ abalathian smelts. I never released a pixie, it was added on its own.

This only happens at this hole, with Charibenet, and has happened twice.

I play on both PC and PS5, it made no difference.