CHANGELOG.md in eco-helpers-2.6.3 vs CHANGELOG.md in eco-helpers-2.6.4

@@ -1,12 +1,19 @@
 # Change Log
 All notable changes to this project will be documented in this file.
 
-## [2.6.4] - 2024-02-xx
+## [2.6.4] - 2024-03-xx
 
 ### Added
 ### Changed
+  - updated core **gem** `ecoportal-api`
+  - The `subordinates` core people property has been removed from the back-end
+    - This was due to some performance issues with org hierarchy model.
+    - As a consequence a temporary patch has been added temporarily in the current gem.
+
 ### Fixed
+  - `Eco::API::UseCases::OozeSamples::RegisterUpdateCase`
+    - initialize `@total_search_results`
 
 ## [2.6.3] - 2024-02-29
 
 ### Changed
   - upgrade `ecoportal-api-v2` **gem**