Cannot register key handlers for the same key with different modifiers

Start by reproducing the behavior with the Set-PSReadLineKeyHandler commands from the issue, then trace the key-handler registration path in PSReadLine. Done means all listed modifier combinations register independently and an unmodified comma remains without a handler.

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

Environment data

PS Version: 7.3.2
PS HostName: ConsoleHost (Windows Terminal)
PSReadLine Version: 2.2.6
PSReadLine EditMode: Windows
OS: 10.0.19041.1 (WinBuild.160101.0800)
BufferWidth: 178
BufferHeight: 56

Steps to reproduce

Paste the following text:

Function Inject-Command([String] $command) {
	[Microsoft.PowerShell.PSConsoleReadLine]::RevertLine()
	[Microsoft.PowerShell.PSConsoleReadLine]::Insert($command)
	[Microsoft.PowerShell.PSConsoleReadLine]::AcceptLine()
}

Set-PSReadLineKeyHandler -Chord "Ctrl+," -ScriptBlock { Inject-Command("echo success") }
Set-PSReadLineKeyHandler -Chord "Alt+," -ScriptBlock { Inject-Command("echo success") }
Set-PSReadLineKeyHandler -Chord "Shift+," -ScriptBlock { Inject-Command("echo success") }
Set-PSReadLineKeyHandler -Chord "Ctrl+Alt+." -ScriptBlock { Inject-Command("echo success") }
Set-PSReadLineKeyHandler -Chord "Ctrl+Shift+," -ScriptBlock { Inject-Command("echo success") }
Set-PSReadLineKeyHandler -Chord "Alt+Shift+," -ScriptBlock { Inject-Command("echo success") }
Set-PSReadLineKeyHandler -Chord "Ctrl+Alt+Shift+," -ScriptBlock { Inject-Command("echo success") }

• Notice the first 4 handlers are able to be registered
• Notice the remaining 3 handlers are not able to be registered
• Type ,
• Notice , is replaced with echo success (this handler was never registered)

Expected behavior

• Each key handler should be able to be registered
• Unmodified , should not have a handler registered

Actual behavior

• Each key handler is not able to be able to be registered
• Unmodified , has a handler registered