Mistress Sassz'ine - Consuming Hunger

I have some confusion regarding this debuff. When a player gets Consuming Hunger, a moment later the icon for it will be duplicated. I assumed that was for the Waverunner, and once a player would stand in Thundershock, both icons would drop off.

However, what I am seeing is that only one icon drops, and the other remains, indicating that standing in Thundershock only removes the Murlock, and not the ticking debuff. As a fight progresses, it only becomes more difficult to figure out what is going on with this debuff. I can even spot players that have the single icon, but don’t seem to be taking dmg, further confusing me as to why they have the icon still applied.

If you look at Damage Taken, there is only one filter for it (id: 230920) - but if you switch to Debuffs, there are 3 listed: 230920, 230384, & 234661. The first seeming to be the “cast of origin” and persistent, the second the Murlock Waverunner in the first phase, and the third the Murlock Tiderunner in the final phase. (dmg same for both Murlocks used)

I’d love to have help understanding it. It’s not so much about “what do?”, than it is understanding fully what is taking place so that I’m satisfied. >.< Curiosity killed the cat… etc, etc.