The recipe for grindstone is using incorrect blocks (endstone brick slabs and warped planks). Manually putting the regular items in the crafting grid does not work either.
How to produce:
Start a survival world.
Get a crafting table.
Search for Grindstone using the search function.
You'll see that it uses the innocent recipe.
Thank you for your report!
We're actually already tracking this issue at MCPE-69420, so I will resolve and link this ticket as a duplicate.
If you would like to add a vote and any extra information to the main ticket it would be appreciated.
If you haven't already, you might like to make use of the search feature to see if the issue has already been mentioned.
Quick Links:
📓 Issue Guidelines – 💬 Community Support – 📧 Customer Support – ✍️ Feedback and Suggestions – 📖 Game Wiki