diff --git a/pkg/datasource/zabbix.go b/pkg/datasource/zabbix.go
index 23ab529..7afb908 100644
--- a/pkg/datasource/zabbix.go
+++ b/pkg/datasource/zabbix.go
@@ -118,10 +118,13 @@ func (ds *ZabbixDatasourceInstance) applyDataProcessing(ctx context.Context, que
 	// Align time series data if possible
 	disableDataAlignment := query.Options.DisableDataAlignment || ds.Settings.DisableDataAlignment || query.QueryType == MODE_ITSERVICE
 	if !disableDataAlignment {
-		if useTrend && !DBPostProcessing {
-			for _, s := range series {
-				// Trend data is already aligned (by 1 hour interval), but null values should be added
-				s.TS = s.TS.FillTrendWithNulls()
+		if useTrend {
+			// Skip if data fetched directly from DB (it already contains nulls)
+			if !DBPostProcessing {
+				for _, s := range series {
+					// Trend data is already aligned (by 1 hour interval), but null values should be added
+					s.TS = s.TS.FillTrendWithNulls()
+				}
 			}
 		} else {
 			for _, s := range series {