Replicate 'max length' field in PrefixFilterForm for consistency

netbox/ipam/forms.py

@@ -437,6 +437,9 @@ class PrefixFilterForm(BootstrapMixin, TenancyFilterForm, CustomFieldFilterForm)
         'q', 'within_include', 'family', 'mask_length', 'vrf_id', 'status', 'region', 'site', 'role', 'tenant_group',
         'tenant', 'is_pool', 'expand',
     ]
+    mask_length__lte = forms.IntegerField(
+        widget=forms.HiddenInput()
+    )
     q = forms.CharField(
         required=False,
         label='Search'

netbox/templates/inc/search_panel.html

@@ -7,7 +7,10 @@
     </div>
     <div class="panel-body">
         <form action="." method="get" class="form">
-                {% for field in filter_form %}
+            {% for field in filter_form.hidden_fields %}
+                {{ field }}
+            {% endfor %}
+            {% for field in filter_form.visible_fields %}
                 <div class="form-group">
                     {% if field.name == "q" %}
                         <div class="input-group">