Campfire blocks when lit have a chance to produce an ember which uses the lava particle
Soul Campfires on the other hand don't have this feature because a soul lava particle does not exist for them, this could be fixed by adding a soul colored lava particle to make it emit embers just like the normal campfire counterpart
Thank you for your report!
We're actually already tracking this issue in MC-185482, so this ticket is being resolved and linked as a duplicate.
However, that ticket has been resolved as working as intended, which means that this is not considered a bug and won't be fixed.
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