Test instance block "Entities" flips when closing UI

When closing the Test instance block UI using "Reset and Load", "Save Structure", "Load and Run", or "Done", the "Entities" toggle is flipped.

How to reproduce:

1. Place down a Test instance block

2. Open the UI

3. ✔ Observe "Entities" is set to "ON"

4. Click "Reset and Load", "Save Structure", "Load and Run", or "Done"

5. Reopen the UI

6. ❌ Observe "Entities" is now set to "OFF"

7. Repeat steps 4 and 5

8. ❌ Observe "Entities" is now set to "ON" again

Also note that the "Reset and Load" and "Save Structure" buttons load/save entities only when "Entities" is set to "OFF". This is possibly caused by the flipping happening before the actual action of the button.