PowerShell ProtectedData.Unprotect Fails in Console but Works in ISE

Question

Im trying to encrypt and decrypt passwords, i've made 2 functions:

function VA-EncryptPassword {
    param(
        [Parameter(Mandatory=$true)]
        [string]$PlainPassword
    )

    # Add assembly for security
    Add-Type -AssemblyName "System.Security"

    # Convert password string to a byte array
    $PlainPasswordBytes = [System.Text.Encoding]::Unicode.GetBytes($PlainPassword)

    # Encrypt the password (machine-specific)
    $EncryptedPassword = [System.Security.Cryptography.ProtectedData]::Protect($PlainPasswordBytes, $null, [System.Security.Cryptography.DataProtectionScope]::LocalMachine)

    # Optionally, convert the byte array to Base64 for easier storage or transmission
    $Encrypted64Password = [Convert]::ToBase64String($EncryptedPassword)

    # Return the Base64 encrypted password
    $Encrypted64Password
}

function VA-DecryptPassword {
    param(
        [Parameter(Mandatory=$true)]
        [string]$Encrypted64Password
    )

    # Add assembly for security
    Add-Type -AssemblyName System.Security
    Add-Type -AssemblyName System.Text.Encoding

    # Convert the Base64 encrypted password back to a byte array
    $EncryptedPasswordBytes = [Convert]::FromBase64String($Encrypted64Password)

    # Decrypt the password using DPAPI
    $DecryptedPasswordBytes = [System.Security.Cryptography.ProtectedData]::Unprotect($EncryptedPasswordBytes, $null, [System.Security.Cryptography.DataProtectionScope]::LocalMachine)

    # Convert byte array back to a string
    $DecryptedPassword = [System.Text.Encoding]::Unicode.GetString($DecryptedPasswordBytes)

    # Return the decrypted password
    $DecryptedPassword
}

I get: exception calling "unprotect" with "3" arguments: "The operation completed successfully" Which means, it runs it but the result is null (?)

It functions correctly on several servers, except 2. The tricky part is, if i run the script in the Powershell ISE, i can do both encrypt and decrypt. However, i can't decrypt do it with neither Console nor' Scheduled Task.

I can encrypt with the console, and decrypt with the ISE. But i can't for the life of me decrypt with console.

I've checked everything i could think of, Env:, $Profile, Features on the serves that work vs. the ones that doesn't, try as admin, regular user, checked .Net Framework and Core versions, and they both run powershell 5.xx (identical)

I hope someone has a bright idea, or has run into the issue themselves.