Setting a key handler for 'Ctrl+Alt+?' sets the same key handler for '?'

Reproduce the behavior with Set-PSReadLineKeyHandler and Get-PSReadLineKeyHandler using '?' and 'Ctrl+Alt+?'. Trace the chord parsing and key-binding lookup, then add a regression test showing that '?' remains unbound and is inserted while 'Ctrl+Alt+?' invokes the configured function.

Prerequisites

• Write a descriptive title.
• Make sure you are able to repro it on the latest released version
• Search the existing issues, especially the pinned issues.

Exception report

N/A

Screenshot

N/A

Environment data

PS Version: 7.3.0
PS HostName: ConsoleHost (Windows Terminal)
PSReadLine Version: 2.2.6
PSReadLine EditMode: Windows
OS: 10.0.25262.1000 (WinBuild.160101.0800)
BufferWidth: 120
BufferHeight: 30

Steps to reproduce

1. Launch PowerShell.
2. Run Set-PSReadLineKeyHandler -Chord 'Ctrl+Alt+?' -Function ShowKeyBindings.
3. Type "?".

Expected behavior

"?" is inserted into the command line.

Actual behavior

The list of key bindings appears. "?" is not inserted into the command line.

Notes

• After step 2, Get-PSReadLineKeyHandler -Chord '?' returns a key binding same with Get-PSReadLineKeyHandler -Chord 'Ctrl+Alt+?'.
• This bug is reproduced with Windows PowerShell 5.1 / PowerShell 7.3.0 on Windows Terminal / conhost.exe.
• This bug is reproduced for other functions such as ShowCommandHelp
• This bug is NOT reproduced for other keys such as 'Ctrl+Alt+K'.