Enderman aggro

Thank you for your report!
We're actually already tracking this issue in MC-53518, so I 've resolved and linked this ticket as a duplicate.

Endermen do not attack endermites, if the mite has been created from an ender pearl. It not being the case for endermites spawned with spawn eggs is intentional.
You can use the command /summon endermite ~ ~ ~ {PlayerSpawned:true} for creative testing.

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 – 📖 Game Wiki