Upgrade to PS7 level module causes script to stop working properly

Import-Module Devolutions.Powershell, psPAS

function Set-MyRDMSessionPassword {
    [cmdletbinding()]
    param(
        [parameter(Mandatory, ParameterSetName = 'plain')]
        [string]$MyPlainPwd,


        [parameter(Mandatory, ParameterSetName = 'crypt')]
        [securestring]$MyPwd,


        [parameter(ValueFromPipelineByPropertyName)]
        [string]$UserName = $env:USERNAME,


        [parameter(ValueFromPipelineByPropertyName)]
        [string]$CredentialGroup = '_Credentials'  #this is just my credentials group in RDM
    )


    Begin {
        if ('ProcessWindowFinder' -as [type]) {
            Write-verbose -Message '[ProcessWindowFinder] is loaded'
        }
        else {
            Write-verbose -message 'Adding [ProcessWindowFinder] accelerator'
            Add-Type -TypeDefinition @'
using System;
using System.Runtime.InteropServices;


public class ProcessWindowFinder
{
    private delegate bool WindowDelegate(IntPtr hWnd, int lParam);

    [DllImport("user32.dll", SetLastError=true)]
    private static extern uint GetWindowThreadProcessId(IntPtr hWnd, out uint processId);

    [DllImport("user32.dll")]
    private static extern bool EnumDesktopWindows(IntPtr hDesktop, WindowDelegate lpfn, IntPtr lParam);

    public static bool FindByPID(uint pid)
    {
        bool found = false;
        ProcessWindowFinder.WindowDelegate filter = delegate(IntPtr hWnd, int lParam)
        {
            if(!found)
            {
                // test whether this window belongs to the target process 
                // if we haven't already found a windows belonging to it
                uint _pid;
                GetWindowThreadProcessId(hWnd, out _pid);
                if(pid == _pid)
                    found = true;
            }

            return true;
        };
        EnumDesktopWindows(IntPtr.Zero, filter, IntPtr.Zero);

        return found;
    }
}
'@
        }


        $RDMPath = (Get-ItemProperty -Path registry::HKEY_LOCAL_MACHINE\SOFTWARE\RemoteDesktopManager -Name InstallationDirectory).InstallationDirectory
        $RDMFilePath = [System.IO.Path]::Combine($RDMPath, 'RemoteDesktopManager.exe')

        $GetMyRDMPID = {
            Get-Process -ProcessName RemoteDesktopManager -IncludeUserName -ErrorAction Stop| 
            Where-Object UserName -match $UserName | 
            Select-Object -ExpandProperty ID  
        }
    }
    Process {
        try {
            $MyRDMProcess = & $GetMyRDMPID
        }
        catch {
            Start-Process -FilePath $RDMFilePath -WorkingDirectory $RDMPath
        }

        do {
            try {
                $MyRDMProcess = & $GetMyRDMPID
                $FoundWindow = [ProcessWindowFinder]::FindByPID($MyRDMProcess)
            }
            catch {
                Start-Sleep -Milliseconds 500
            }
        } until ($FoundWindow)
        Start-Sleep -seconds 1
        
        $MyRDMSessions = Get-RDMSession -GroupName $CredentialGroup | Where-Object name -match $UserName

        if ($PSCmdlet.ParameterSetName -eq 'plain') {
            $MyPwd = $MyPlainPwd | ConvertTo-SecureString -AsPlainText -Force
        }

        foreach ($Session in $MyRDMSessions) {
            Set-RDMSessionPassword -ID $Session.ID -Password $MyPwd -Refresh -SetSession
        }
        Update-RDMUI
        'Password Update attempt complete'
    }
    
}