Powershell behind NTLM proxy

Followed scripts set Powershell's proxy credentials as current default credentials (as in Internet Explorer).

$browser = New-Object System.Net.WebClient
$browser.Proxy.Credentials =[System.Net.CredentialCache]::DefaultNetworkCredentials

For more details, read here.

Error of Update-Help

PS F:\> update-help
update-help : Failed to update Help for the module(s) 'AppBackgroundTask, AppLocker, Appx, AssignedAccess, BitLocker,
BitsTransfer, BranchCache, CimCmdlets, Defender, DirectAccessClientComponents, Dism, DnsClient,
EventTracingManagement, HgsClient, Hyper-V, International, iSCSI, ISE, Kds, Microsoft.PowerShell.Archive,
Microsoft.PowerShell.Core, Microsoft.PowerShell.Diagnostics, Microsoft.PowerShell.Host,
Microsoft.PowerShell.Management, Microsoft.PowerShell.ODataUtils, Microsoft.PowerShell.Security,
Microsoft.PowerShell.Utility, Microsoft.WSMan.Management, MMAgent, MsDtc, NetAdapter, NetConnection,
NetEventPacketCapture, NetLbfo, NetNat, NetQos, NetSecurity, NetSwitchTeam, NetTCPIP, NetWNV,
NetworkConnectivityStatus, NetworkSwitchManager, NetworkTransition, PackageManagement, PcsvDevice, PKI, PnpDevice,
PowerShellGet, PrintManagement, PSDesiredStateConfiguration, PSReadline, PSScheduledJob, PSWorkflow,
PSWorkflowUtility, ScheduledTasks, SecureBoot, SmbShare, SmbWitness, StartLayout, Storage, TLS, TroubleshootingPack,
TrustedPlatformModule, VpnClient, Wdac, WindowsDeveloperLicense, WindowsErrorReporting, WindowsSearch, WindowsUpdate'
with UI culture(s) {en-US} : Unable to connect to Help content. The server on which Help content is stored might not
be available. Verify that the server is available, or wait until the server is back online, and then try the command
again.
At line:1 char:1
+ update-help

+ ~~~~~~~~~~~
    + CategoryInfo          : InvalidOperation: (:) [Update-Help], Exception
    + FullyQualifiedErrorId : UnableToConnect,Microsoft.PowerShell.Commands.UpdateHelpCommand