This happens when you update blocks' state.
Steps to reproduce:
Remember to set your game mode to survival.
1) Get yourself a shovel with the enchantment of Efficiency, at least level IV.
2) Mining dirt blocks quickly and observe when those blocks actually disappear.
3) Get yourself a stack of dirt blocks.
4) Place them in a line quickly and observe when those blocks actually appear.
Expected:
They should appear or disappear visually at the point when you placing or mining.
Observed:
Sometimes they remain invisible or stay still for a second after you placing or mining.
Thank you for your report!
We're tracking this issue in MCPE-33749 and MCPE-59935, so this ticket is being resolved and linked as a duplicate.
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