When the Enderdragon spits it’s fireball, and it explodes into dragon’s breath, the hurt box seems to be spherical, yet the hit of which you can collect it is a flat circle. You could be under the dragon’s breath and not in the particles, yet it can still hurt you. Also, it occasionally turns invisible, but it can still hurt you.
Thank you for your report!
We're actually already tracking this issue under MCPE-51214 so I've requested this report be resolved and linked as a duplicate.
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