diff --git a/LibreNMS/Util/Url.php b/LibreNMS/Util/Url.php
index bc1f13ea54..af7271f1e9 100644
--- a/LibreNMS/Util/Url.php
+++ b/LibreNMS/Util/Url.php
@@ -139,7 +139,7 @@ class Url
             $text = $label;
         }
 
-        $content = '<div class=list-large>' . addslashes(htmlentities($port->device->displayName() . ' - ' . $label)) . '</div>';
+        $content = '<div class=list-large>' . addslashes(htmlentities(optional($port->device)->displayName() . ' - ' . $label)) . '</div>';
         if ($description = $port->getDescription()) {
             $content .= addslashes(htmlentities($description)) . '<br />';
         }
@@ -230,7 +230,7 @@ class Url
      */
     public static function deviceUrl($device, $vars = [])
     {
-        $routeParams = [is_numeric($device) ? $device : $device->device_id];
+        $routeParams = [($device instanceof Device) ? $device->device_id : (int) $device];
         if (isset($vars['tab'])) {
             $routeParams[] = $vars['tab'];
             unset($vars['tab']);
diff --git a/app/Http/Controllers/PaginatedAjaxController.php b/app/Http/Controllers/PaginatedAjaxController.php
index 1a91bcbd63..4d9454bc05 100644
--- a/app/Http/Controllers/PaginatedAjaxController.php
+++ b/app/Http/Controllers/PaginatedAjaxController.php
@@ -146,9 +146,18 @@ abstract class PaginatedAjaxController extends Controller
     protected function filter($request, $query, $fields)
     {
         foreach ($fields as $target => $field) {
-            if (is_callable($field)) {
-                $field($query, $request->get($target));
-            } elseif (($value = $request->get($field)) !== null) {
+            $callable = is_callable($field);
+            $value = $request->get($callable ? $target : $field);
+
+            // unfiltered field
+            if ($value === null) {
+                continue;
+            }
+
+            // apply the filter
+            if ($callable) {
+                $field($query, $value);
+            } else {
                 $value = $this->adjustFilterValue($field, $value);
                 if (is_string($target)) {
                     $query->where($target, $value);
diff --git a/app/Http/Controllers/Table/PortsController.php b/app/Http/Controllers/Table/PortsController.php
index 499f8e4cf2..4010753377 100644
--- a/app/Http/Controllers/Table/PortsController.php
+++ b/app/Http/Controllers/Table/PortsController.php
@@ -155,7 +155,7 @@ class PortsController extends TableController
             'status' => $status,
             'device' => Url::deviceLink($port->device),
             'port' => Url::portLink($port),
-            'secondsIfLastChange' => ceil($port->device->uptime - ($port->ifLastChange / 100)),
+            'secondsIfLastChange' => ceil(optional($port->device)->uptime - ($port->ifLastChange / 100)),
             'ifConnectorPresent' => ($port->ifConnectorPresent == 'true') ? 'yes' : 'no',
             'ifSpeed' => $port->ifSpeed,
             'ifMtu' => $port->ifMtu,
diff --git a/app/Models/Port.php b/app/Models/Port.php
index d123d87e74..9b4e9aa7b5 100644
--- a/app/Models/Port.php
+++ b/app/Models/Port.php
@@ -61,7 +61,7 @@ class Port extends DeviceRelatedModel
      */
     public function getLabel()
     {
-        $os = $this->device->os;
+        $os = optional($this->device)->os;
 
         if (\LibreNMS\Config::getOsSetting($os, 'ifname')) {
             $label = $this->ifName;