diff --git a/dashboards-reports/server/routes/utils/dataReportHelpers.ts b/dashboards-reports/server/routes/utils/dataReportHelpers.ts
index f20acc96..3b56f6ed 100644
--- a/dashboards-reports/server/routes/utils/dataReportHelpers.ts
+++ b/dashboards-reports/server/routes/utils/dataReportHelpers.ts
@@ -235,6 +235,8 @@ function traverse(data, keys, result = {}) {
  */
 function sanitize(doc: any) {
   for (const field in doc) {
+    if (doc[field] == null)
+      continue
     if (
       doc[field].toString().startsWith('+') ||
       (doc[field].toString().startsWith('-') && typeof doc[field] !== "number") ||