Relates to MC-215436, MC-308964 and MC-311734.
With the most recent snapshot’s fixing of MC-195836, the subtitle for the sound played when breaking a fire or soul fire block (minecraft:block.fire.extinguish) has been changed from “Fire extinguished” to “Fire extinguishes”. This means it now displays identically to the sound played when an entity on fire is put out by force (minecraft:entity.generic.extinguish_fire), but is nonetheless given a separate line.
In general, this is something that captions just should not do.
To fix: since you are destroying a block in the world, minecraft:block.fire.extinguish should use subtitles.block.generic.break for its subtitle text, as no other block gets special treatment in this regard. The entity extinguishing sound can probably remain as it is.
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