Technicians Receive Push Notifications for Service Appointments Assigned to Other Service Resources in Field Service Mobile App

Root Cause

Two independent components interact to cause cross-technician notifications:

1. The Field Service Lightning (FSL) Managed Package automatically adds the assigned resource as a Chatter follower (EntitySubscription) of both the Service Appointment and the parent Work Order when a Service Appointment is dispatched. This means every technician assigned to any Service Appointment on a Work Order becomes a follower of that entire Work Order.
2. Third-party managed package flows (such as FSL_ServiceAppointment_Update_Notification) fire when a Service Appointment status changes and send push notifications to all Work Order followers, without filtering to only the assigned resource of the specific Service Appointment that changed.

Steps to Resolve

Step 1: Disable Automatic Work Order Follower Creation in Field Service Settings

1. Navigate to Setup.
2. Go to App Launcher and search for Field Service Settings.
3. Click Field Service Settings.
4. Navigate to the Sharing section.
5. Click the Scheduled Jobs tab.
6. Disable the following settings:
   1. "Share parent Work Order when Service Appointment is shared"
   2. "Make assigned resources followers of service appointments that are Dispatched or In Progress"
7. Click Save.

Step 2: Clean Up Existing Follower Records

Existing EntitySubscription records — which represent Chatter follower relationships — continue triggering notifications until they are removed. Use the Salesforce Object Query Language (SOQL) query below to identify and delete them.
For example, if your org has Work Order WO-0001234 where Technician A and Technician B are both receiving each other's notifications, run this query for that Work Order's ID first:
SELECT Id, SubscriberId, ParentId FROM EntitySubscription WHERE ParentId = '<WorkOrderId>'
This query returns all Chatter follower records (EntitySubscription) for the specified Work Order, including the subscriber user IDs. Each returned record represents a technician who receives notifications from third-party flows targeting Work Order followers.

1. Replace <WorkOrderId> with the ID of the affected Work Order.
2. Note all returned EntitySubscription record IDs.
3. Delete the EntitySubscription records for each affected Work Order.
4. Repeat for all Work Orders where cross-technician notifications have occurred.

Step 3: Contact Your Third-Party Package Vendor

Reach out to your third-party managed package vendor (if you are using custom notification solution with third-party app) and request:

1. Confirmation that their notification flow uses Work Order followers as the recipient list.
2. A configuration option or package update to scope notifications to only the assigned resource of the specific Service Appointment that changed status — not all Work Order followers.