A sequence of undone changes cannot be redone past the last one

Describe the bug
A sequence of undone changes cannot be redone past the last one. Possible data loss.

To Reproduce
Steps to reproduce the behavior:

1. Make some changes
2. Undo 5 times with u
3. Redo 5 times with ctrl+r
4. Only the first redo (of the last undo) works

Expected behavior
All undone changes are re-applied.

Screenshots
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Environment (please complete the following information):

• Extension (VsCodeVim) version: v1.23.2
• VSCode version: 1.71.0-insider b0895f9
• OS: macOS

Additional context

• Sometimes it works, but when it doesn’t it’s a data loss scenario unless the file was saved before the undo took place.
• A few days ago I had to re-write a couple dozen LoC from memory due to this bug.
• Didn’t happen until the last time I let VSC and extension upgrade themselves. Now it happens every day many times.
• Increasing undo history to 500+ didn’t help.

Start by reproducing the issue in VSCodeVim with u and ctrl+r, using the versions and macOS environment listed in the report. Trace the extension's undo and redo handling to determine why only the first of five redos succeeds. Done means five consecutive undos can all be followed by five successful redos without losing changes.