The Bug
When lava is poured on a water block with sea grass on it, it fails to destroy the sea grass. It does destroy tall sea grass.
Replicate
do a set sea grass command
Place lava over the sea grass
Notice that the lava doesn't destroy the sea grass
Thank you for your report!
We're actually already tracking this issue in MC-129731, so I resolved and linked this ticket as a duplicate.
However, that ticket has already been resolved. That means that this is not considered a bug and won't be fixed. Please do not leave a comment on the linked ticket.
If you haven't already, you might like to make use of the search feature in the future to see if the issue has already been reported.
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