When a skeleton is standing on slabs and is right up to you and starts shooting arrows, it sometimes doesn't hurt you.
Steps to reproduce:
Create a platform of slabs of any type of block
Spawn a skeleton at night time
Don't do anything and wait for it to walk right up to you
Thank you for your report!
We're actually already tracking this issue in MC-157645, so I resolved and linked 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 in the future to see if the issue has already been reported.
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