[BUG]: gMSA account not recognized by config

[wabbitde]

What happened?

The config tool does not recognize a gMSA account correctly.

• unattended throws the error below
• interactive keeps prompting for password when leaving it blank
• interactive using NETWORK SERVICE and then changing to the gMSA account in the Services.msc works

Versions

agent v4.270.0 / RuntimeInformation: Microsoft Windows 10.0.17763. (Windows 2019)

Environment type (Please select at least one enviroment where you face this issue)

• Self-Hosted
• Microsoft Hosted
• VMSS Pool
• Container

Azure DevOps Server type

dev.azure.com (formerly visualstudio.com)

Azure DevOps Server Version (if applicable)

No response

Operation system

Windows Server 2019

Version controll system

No response

Relevant log output

[2026-03-24 05:36:11Z INFO CommandSettings] Arg 'windowslogonaccount': 'office\msa_devops_srvr$'
[2026-03-24 05:36:11Z INFO WindowsServiceControlManager] LogonAccount after transforming: office\msa_devops_srvr$, user: msa_devops_srvr$, domain: office
[2026-03-24 05:36:11Z WARN NativeWindowsServiceHelper] NetIsServiceAccount return code is 3221225782
[2026-03-24 05:36:11Z INFO CommandSettings] Arg 'windowslogonpassword': ''
[2026-03-24 05:36:11Z INFO CommandSettings] Flag 'unattended': 'True'
[2026-03-24 05:36:11Z INFO PromptManager] ReadValue
[2026-03-24 05:36:11Z WARN WindowsServiceControlManager] LogonAccount office\msa_devops_srvr$ is not managed service account, although you did not specify WindowsLogonPassword - maybe you wanted to use managed service account? Please see https://aka.ms/gmsa for guidelines to set up sMSA/gMSA account. 
[2026-03-24 05:36:11Z WARN WindowsServiceControlManager] Value cannot be null. (Parameter 'Invalid configuration provided for windowslogonpassword. Terminating unattended configuration.')
[2026-03-24 05:36:12Z ERR  Agent] System.ArgumentNullException: Value cannot be null. (Parameter 'Invalid configuration provided for windowslogonpassword. Terminating unattended configuration.')
   at Microsoft.VisualStudio.Services.Agent.Listener.Configuration.PromptManager.ReadValue(String argName, String description, Boolean secret, String defaultValue, Func`2 validator, Boolean unattended) in D:\a\_work\1\s\src\Agent.Listener\Configuration\PromptManager.cs:line 76
   at Microsoft.VisualStudio.Services.Agent.Listener.CommandSettings.GetArgOrPrompt(String argValue, String name, String description, String defaultValue, Func`2 validator) in D:\a\_work\1\s\src\Agent.Listener\CommandSettings.cs:line 728
   at Microsoft.VisualStudio.Services.Agent.Listener.CommandSettings.GetWindowsLogonPassword(String accountName) in D:\a\_work\1\s\src\Agent.Listener\CommandSettings.cs:line 461
   at Microsoft.VisualStudio.Services.Agent.Listener.Configuration.WindowsServiceControlManager.ConfigureService(AgentSettings settings, CommandSettings command) in D:\a\_work\1\s\src\Agent.Listener\Configuration.Windows\WindowsServiceControlManager.cs:line 81
   at Microsoft.VisualStudio.Services.Agent.Listener.Configuration.ConfigurationManager.ConfigureAsync(CommandSettings command) in D:\a\_work\1\s\src\Agent.Listener\Configuration\ConfigurationManager.cs:line 415
   at Microsoft.VisualStudio.Services.Agent.Listener.Agent.ExecuteCommand(CommandSettings command) in D:\a\_work\1\s\src\Agent.Listener\Agent.cs:line 107
[2026-03-24 05:36:12Z ERR  Terminal] WRITE ERROR: Value cannot be null. (Parameter 'Invalid configuration provided for windowslogonpassword. Terminating unattended configuration.')