Bugfix/cash balance update related to activities in custom currency (#7616)

* Fix cash balance update related to activities in custom currency

* Update changelog

CHANGELOG.md

@@ -5,6 +5,12 @@ All notable changes to this project will be documented in this file.
 The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/),
 and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0.html).
 
+## Unreleased
+
+### Fixed
+
+- Fixed the cash balance update related to activities in a custom currency
+
 ## 3.50.0 - 2026-08-13
 
 ### Changed

apps/api/src/app/activities/activities.service.ts

@@ -308,7 +308,7 @@ export class ActivitiesService {
         accountId,
         userId,
         amount: amount.toNumber(),
-        currency: data.SymbolProfile.connectOrCreate.create.currency,
+        currency: activity.currency ?? activity.SymbolProfile.currency,
         date: data.date as Date
       });
     }