Azure REST API Response Results Depend on Requester's Region/IP

Question

I have been investigating unexpected behaviour when making REST API requests to Azure APIs. To summarize, If I create a resource in Azure (A SQL Server in East US 2 in a resource group in South Central US) and then make a REST API request (https://management.azure.com/subscriptions/{subscription_id}/resourceGroups/{resource_group}/providers/Microsoft.Sql/servers?api-version=2021-02-01-preview) from one location (Oregon) and from another region (Ohio) the response to the first request includes the new SQL Server while the request to the second request returns an empty response ({"value":[]}).

Responses from Oregon include the following header:

x-ms-routing-request-id:    WESTUS:20210524T044715Z:<GUID>

while responses from Ohio include the

x-ms-routing-request-id:    CANADACENTRAL:20210524T040453Z:<GUID>

It takes around 15 minutes for requests from the second region to start returning responses with the server included. This behaviour is not limited to SQL Servers, that was only one example.

Is this behaviour expected and documented somewhere or is it a bug? Is there a way avoid the 15 minute delay regardless of where the request is sent from?