diff --git a/DnsServerCore/Dns/Zones/CacheZone.cs b/DnsServerCore/Dns/Zones/CacheZone.cs
index bf896269..ddc4b7d7 100644
--- a/DnsServerCore/Dns/Zones/CacheZone.cs
+++ b/DnsServerCore/Dns/Zones/CacheZone.cs
@@ -76,36 +76,39 @@ namespace DnsServerCore.Dns.Zones
 
         public bool SetRecords(DnsResourceRecordType type, IReadOnlyList<DnsResourceRecord> records, bool serveStale)
         {
+            if (records.Count == 0)
+                return false;
+
             bool isFailureRecord = false;
 
-            if (records.Count > 0)
+            if (records[0].RDATA is DnsCache.DnsSpecialCacheRecordData splRecord)
             {
-                if (records[0].RDATA is DnsCache.DnsSpecialCacheRecordData splRecord)
+                if (splRecord.IsFailureOrBadCache)
                 {
-                    if (splRecord.IsFailureOrBadCache)
-                    {
-                        //call trying to cache failure record
-                        isFailureRecord = true;
+                    //call trying to cache failure record
+                    isFailureRecord = true;
 
-                        if (_entries.TryGetValue(type, out IReadOnlyList<DnsResourceRecord> existingRecords))
-                        {
-                            if ((existingRecords.Count > 0) && !(existingRecords[0].RDATA is DnsCache.DnsSpecialCacheRecordData existingSplRecord && existingSplRecord.IsFailureOrBadCache) && !DnsResourceRecord.IsRRSetExpired(existingRecords, serveStale))
-                                return false; //skip to avoid overwriting a useful record with a failure record
-                        }
+                    if (_entries.TryGetValue(type, out IReadOnlyList<DnsResourceRecord> existingRecords) && (existingRecords.Count > 0) && !DnsResourceRecord.IsRRSetExpired(existingRecords, serveStale))
+                    {
+                        if ((existingRecords[0].RDATA is not DnsCache.DnsSpecialCacheRecordData existingSplRecord) || !existingSplRecord.IsFailureOrBadCache)
+                            return false; //skip to avoid overwriting a useful record with a failure record
+
+                        //copy extended errors from existing spl record
+                        splRecord.CopyExtendedDnsErrorsFrom(existingSplRecord);
                     }
                 }
-                else if ((type == DnsResourceRecordType.NS) && (records[0].RDATA is DnsNSRecordData ns) && !ns.IsParentSideTtlSet)
+            }
+            else if ((type == DnsResourceRecordType.NS) && (records[0].RDATA is DnsNSRecordData ns) && !ns.IsParentSideTtlSet)
+            {
+                //for ns revalidation
+                if (_entries.TryGetValue(DnsResourceRecordType.NS, out IReadOnlyList<DnsResourceRecord> existingNSRecords))
                 {
-                    //for ns revalidation
-                    if (_entries.TryGetValue(DnsResourceRecordType.NS, out IReadOnlyList<DnsResourceRecord> existingNSRecords))
+                    if ((existingNSRecords.Count > 0) && (existingNSRecords[0].RDATA is DnsNSRecordData existingNS) && existingNS.IsParentSideTtlSet)
                     {
-                        if ((existingNSRecords.Count > 0) && (existingNSRecords[0].RDATA is DnsNSRecordData existingNS) && existingNS.IsParentSideTtlSet)
-                        {
-                            uint parentSideTtl = existingNS.ParentSideTtl;
+                        uint parentSideTtl = existingNS.ParentSideTtl;
 
-                            foreach (DnsResourceRecord record in records)
-                                (record.RDATA as DnsNSRecordData).ParentSideTtl = parentSideTtl;
-                        }
+                        foreach (DnsResourceRecord record in records)
+                            (record.RDATA as DnsNSRecordData).ParentSideTtl = parentSideTtl;
                     }
                 }
             }