While I was in the game, I went down to the mine. I found this (png) while searching for lava to go to the Nether. In this way, cobblestone should be formed while there is water on the lava. But here the water seems to have stopped because it is lava. This should be fixed.
Thank you for your report!
We're tracking this issue as MCPE-7284, so this ticket is being resolved and linked as a duplicate.
That ticket has already been resolved as Won't Fix, which means this is considered a bug but won't be fixed. The description of that ticket or the comments might explain the rationale. Please do not leave a comment on the linked ticket.
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