Unable to expand MultiElementListEntry in v17

[70CentsApple]

It can be reproduced even in the Cloth Config demo:

This pair should contract when I click on it, and in v16 it surely does! But in v17, it just remain there with nothing changed, so there must be some breaking changes between v16 and v17.

Also, an unexpanded element won't expand when I click on it as well, which is quite annoying.

70CentsApple/ChatTools#61