Selection box in a vector costume appears on the Stage, the affected shape sometimes can't be moved

[nimeratus]

https://scratch.mit.edu/discuss/topic/633326/

Expected Behavior

The selection box doesn't appear on the Stage. All of the shapes can be moved with the selection tool.

Actual Behavior

The selection box appears on the Stage, and the affected shape can't be moved if there are other shapes in the costume. The costume can be saved in this invalid state.

Steps to Reproduce

1. Go to 'https://scratch.mit.edu/projects/editor'
2. Switch to a vector costume
3. Select a vector shape
4. Open a color dialog
5. Change the color
6. Don't close the color dialog
7. Click and hold one of the resize handles on the selection box
   Note: the selection box appears on the stage, but it disappears if the mouse is released
8. While holding the mouse button, right click
9. If there are unselected shapes then the selection is permanently stuck, and the selected shape can't be moved anymore

System Details

I've tested it on Windows 10, Chrome 139

Screenshots