Edit group doesn't get undone correctly

[daxian-dbw]

Environment

PS version: 7.0.0
PSReadline version: 2.1.0-beta1
os: 10.0.18362.1 (WinBuild.160101.0800)
PS file version: 7.0.0.0
HostName: ConsoleHost (Windows Terminal)
BufferWidth: 150
BufferHeight: 40

Steps to reproduce

1. Make sure you are in VI edit mode
2. Type yuiogh and then press Escape
3. Press LeftArrow and then Shift+c to remove gh at the end
4. Type 789 and then Ctrl+z
5. Press 1 and then press Escape
6. Press u to undo the edit group

Expected behavior

Edits since Shift+c should be undone, and console should show yuiogh

Actual behavior

The console shows yuiog