/reload all no longer works in editor mode test sessions

The bug

When using /reload all in an editor mode test session in 26.30.26 preview, the following error appears:

Non-Editor world only accepts vanilla connections
An error has occurred.

The user is booted out of the world altogether.

This did not occur in the previous preview.

How to reproduce

1. Start the game in editor mode (if you can figure it out)

2. Create or open a project

3. Click “Test World” then “Test World”

4. Type /reload all

Expected behavior

All packs should reload as you are returned to the ongoing test sestion

Observed behavior

Error message appears