Intellisense (file and directory) suggestions not appearing for $ENV paths

Reproduce the empty completion behavior in the VS Code editor and integrated terminal using $ENV:APPDATA\, with the listed VS Code and PowerShell versions and completion settings. Trace the extension's handling of environment-variable file paths; done means file and directory suggestions appear and editor Tab completion works without regressing terminal completion.

Prerequisites

• I have written a descriptive issue title.
• I have searched all open and closed issues to ensure it has not already been reported.
• I have read the troubleshooting guide.
• I am sure this issue is with the extension itself and does not reproduce in a standalone PowerShell instance.
• I have verified that I am using the latest version of Visual Studio Code and the PowerShell extension.
• If this is a security issue, I have read the security issue reporting guidance.

Summary

Scenario:

• $ENV:APPDATA\ is typed in an editor and/or the integrated terminal (either PS 5.1 or 7+ -- both behave the same way)
• Using a fresh install of VS Code with default settings (except tab completion, which is enabled) in Windows Sandbox
• Enabled settings:
  • editor.suggest.showFiles
  • editor.suggest.showFolders
  • editor.tabCompletion

Behavior:

Editor Window

• ❌ Pressing Ctrl+Spacebar one or more times displays (an empty) suggestions box
• ❌ Pressing TAB inserts a tab character rather than performing tab completion

Integrated Terminal

• ❌ Pressing Ctrl+Spacebar once displays (an empty) suggestions box
  • ✔ Pressing Ctrl+Spacebar a second time triggers PSReadLine's MenuComplete function, and paths are correctly expanded/displayed
• ✔ Pressing TAB performs tab completion, and paths are correctly expanded/displayed

PowerShell Version

PS C:\> $PSVersionTable; $Host                                             

Name                           Value
----                           -----
PSVersion                      7.6.3
PSEdition                      Core
GitCommitId                    7.6.3
OS                             Microsoft Windows 10.0.19041
Platform                       Win32NT
PSCompatibleVersions           {1.0, 2.0, 3.0, 4.0, 5.0, 5.1, 6.0, 7.0}
PSRemotingProtocolVersion      2.4
SerializationVersion           1.1.0.1
WSManStackVersion              3.0

Name             : Visual Studio Code Host
Version          : 2025.4.0
InstanceId       : 91c2ed31-fa5d-44e7-87ea-4a7eb71a2030
UI               : System.Management.Automation.Internal.Host.InternalHostUserInterface
CurrentCulture   : en-US
CurrentUICulture : en-US
PrivateData      : Microsoft.PowerShell.ConsoleHost+ConsoleColorProxy
DebuggerEnabled  : True
IsRunspacePushed : False
Runspace         : System.Management.Automation.Runspaces.LocalRunspace

Visual Studio Code Version

PS C:\> code --version
1.125.0
93cfdd489c3b228840d0f86ec77c3636277c93ea
x64

Extension Version

PS C:\> code --list-extensions --show-versions | Select-String powershell

ms-vscode.powershell@2025.4.0

Steps to Reproduce

1. Type an environment path variable in an editor window, e.g. $ENV:APPDATA\
2. Press Ctrl+Spacebar
3. Witness the empty suggestions box
4. Breath

Visuals

https://github.com/user-attachments/assets/ce4ef679-2296-4a4d-a16a-633fc10ed720

Logs

No response