Tab completion incorrectly re-escapes already escaped path

[erhhung]

Here are some directories and files on a macOS system
(only showing entries as examples relevant to this issue):

~/Library/
    Application\ Scripts/
    Application\ Support/
        .DS_Store
        AddressBook
        App\ Store
        AskPermission
        DVD\ Player

I have the latest .fzf_bash_completion script loaded—although the issue has been around for quite some time—and I have neither of the auto common prefix options (FZF_COMPLETION_AUTO_COMMON_PREFIX and FZF_COMPLETION_AUTO_COMMON_PREFIX_PART) defined, so base completion behavior...

$ ls ~/Lib<tab>
This works fine as there's only one match.
$ ls ~/Library/(cursor after added slash)

$ ls ~/Library/<tab>
Popup appears with entries. For example:

> ls ~/Library/
─────────────────────────────────
▶ ~/Library/.DS_Store
  ~/Library/.localized
  ~/Library/Accessibility/
  ~/Library/Accounts/
  ~/Library/AppleMediaServices/
  ~/Library/Application\ Scripts/
  ~/Library/Application\ Support/
  ~/Library/Assistant/
  ~/Library/Assistants/

Note that Application\ Support/ is backslash-escaped in the list.

FWIW, I also use Amazon Q CLI autocomplete, and names containing spaces are shown not-escaped in their popup, i.e. Application Support/

I choose ~/Library/Application\ Support/ and hit Enter.
$ ls ~/Library/Application\ Support/(cursor immediately after slash)
So far so good, so I just hit Tab again.

$ ls ~/Library/Application\ Support/<tab>
Popup appears with bad entries. For example:

> ls ~/Library/Application\ Support/
────────────────────────────────────────────────
▶ ~/Library/Application\\\ Support/.DS_Store
  ~/Library/Application\\\ Support/AddressBook
  ~/Library/Application\\\ Support/App\ Store
  ~/Library/Application\\\ Support/AskPermission
  ~/Library/Application\\\ Support/DVD\ Player

Note that the existing path is now re-escaped ("\ " becomes "\\\ ") while base entry names are only backslash-escaped as needed, like before.

I choose ~/Library/Application\\\ Support/App\ Store and hit Enter.
$ ls ~/Library/Application\\\ Support/App\ Store (cursor after space but no slash)
If I hit Enter now, I obviously get "No such file or directory"

I would have expected to see:
$ ls ~/Library/Application\ Support/App\ Store/(cursor immediately after slash)