Python/JS editor: “Undo” and "Redo" button not take effect

[Sheila111]

Describe the bug
Python/JS editor: “Undo” and "Redo" button not take effect

Steps to reproduce the behavior
1.Navigate to https://makecode.microbit.org/beta#
2.Create a new project
3.Add code and click “Undo” and "Redo" button

Expect behavior
“Undo” and "Redo" button takes effect as in Blocks editor

Actual behavior
Python/JS editor: “Undo” and "Redo" button not take effect

Additional context
1.OS: Windows(rs6)
2.makecode.microbit.org version: 3.1.75
3.Microsoft MakeCode version: 6.13.18

[Sheila111]

Also happened on Mac