We have an Azure Sitecore 10.3 setup to which we have added an additional CD app service which is on a different region. For the sites hosted in this app service, the XDB functionalities are not working whereas it's working for sites hosted on the CD app which comes with Sitecore default setup. From the logs, we could see the **XdbCollectionUnavailableexception : the HTTP response was not successful: NotFound (screenshot attached).**
We have verified the certificate thumbprint in configs and app service configuration and all seems correct. Can anyone help with this issue?