Undo-Fu-Session discarding: "No further undo information"

### I confirm that...

- [X] I have searched the [issue tracker](https://github.com/doomemacs/doomemacs/issues), [documentation](https://docs.doomemacs.org), [FAQ](https://docs.doomemacs.org/-/faq), [Discourse](https://discourse.doomemacs.org), and [Google](https://google.com), in case this issue has already been reported/resolved.

- [X] I have read "[How to Debug Issues](https://doomemacs.org/d/how2debug)", and will use it to provide as much information about this issue as possible.

- [X] The issue can be reproduced on the **latest** available commit of Doom.

- [X] The issue can be reproduced on a stable release of Emacs, such as 27 or 28. *(Doom does not support development builds like 29+ or any version ending in .50 or .9x)*

### Expected behavior

Press u in normal state to undo the most recent change.

### Current behavior

The message "No further undo information" is displayed.

By pressing `SPC h e`, I identified two errors:
- Undo-Fu-Session discarding: file length mismatch for "\"
- Undo-Fu-Session discarding undo data: file checksum mismatch for "\"

I believe these errors mean that Undo-Fu-Session has missed a beat and gave up completely.
Is there some way to ensure that this never happens?
Hooks that save/load undo history when closing/opening a file?

I cannot get the persistent undo feature to work consistently in Doom Emacs.
I have tried all sorts of undo settings, but took them all out of my config because nothing was working.
I tried re-installing Doom Emacs with different Emacs versions.

### Steps to reproduce

1. Load my config:
a. https://github.com/maptv/setup/blob/main/config.el
b. https://github.com/maptv/setup/blob/main/packages.el
2. Open a file
3. Make a change
4. Exit the current session
5. Start a new session
6. Press u

### System Information

https://gist.github.com/maptv/5afef3d77ee4378f44eeccf8b833475e