The chat scroll bar no longer renders

The Bug:

The chat scroll bar no longer renders.

This issue first appeared in 23w18a.

Steps to Reproduce:

1. Type more than twenty messages in chat.
2. Open chat and attempt to locate the chat scroll bar.
3. Take note as to whether or not the chat scroll bar no longer renders.

Observed Behavior:

The chat scroll bar no longer renders.

Expected Behavior:

The chat scroll bar would render.