SAP OData Call to Different Backends ( 403 Error)

[MayankSaxena]

I am working on an SAPUI5 project where I need to call two OData services originating from different backend systems:

1. One service comes from an On-Premise S/4 HANA system.
2. The other service is from an ABAP Cloud environment hosted in SAP BTP.

Individually, both services work perfectly. However, when I try to call both within the same project, I encounter a 403 Forbidden error for the service that is called using the unnamed model ( means the service which is added later as secondary service) .

I am using BAS as my IDE and adding the services using Service Manager. I am not calling the Odata service with any method. I am directly binding  the entities on the page with two different tables. 

Has anyone faced a similar issue or knows how to resolve this? Any insights on handling multiple OData services from different backends in an SAPUI5 application would be greatly appreciated.