When a Sponge is placed next to a water source block over Soul Sand or Magma Blocks the source block stays until updated.
[media]Linked issues
Comments 3
relates to MCPE-57063 and MCPE-34497. I have reproduced both of these on Android as well in the latest versions.
I cannot reproduce this in 1.16.20. It was probably fixed with the fix to MCPE-34497 and MCPE-57063.
What is going on? Sounds like you gotta call up the minecraft ghost busters on this one of sounds life another invisible ghostly one.