Attachable position does not update when rendered geometry changes

The bug

If an entity render controller changes the active geometry, attachables do not move to match the new bone structure. Relogging fixes the problem.

How to reproduce

1. Download and open the attached world. You should see a husk with a helmet on its head
2. Run /event entity @e[type=sheep] v1

Expected results
The husk should turn into a sheep, and the helmet should move to the sheep's head

Observed results
The helmet doesn't move until you relog. Then the opposite problem happens.