try to use console button

app/UI/Vms/Buttons/ConsoleButton.php

@@ -32,7 +32,7 @@ class ConsoleButton extends ButtonDataTableModalAction implements ClientArea
     {
         $this->initIds('consoleButton');
         $this->setDisableByColumnValue("vmid", 0);
-        $url ="clientarea.php?action=productdetails&id={$this->getWhmcsParamByKey('serviceid')}&modop=custom&a=management&mg-page=console&mg-action=novnc";
+        $url ="window.open('clientarea.php?action=productdetails&id={$this->getWhmcsParamByKey('serviceid')}&modop=custom&a=management&mg-page=console&mg-action=novnc', '', 'width=900,height=700'); return false;";
 //        $url ="clientarea.php?action=productdetails&id={$this->getWhmcsParamByKey('serviceid')}&modop=custom&a=management&mg-page=vm";
         $this->setRawUrl($url)
             ->setRedirectParams(['vm' => ':id']);