Azure Api Management - Backend API returns unauthenticated 401 even on using correct token

Question

Hello,

I am using Azure B2C as identity provider, the generated bearer token is valid and can be used to access the api protected by this when accessed directly, the api being hosted as an app service.

But when the same api is accessed using the end point provided by azure api management gateway it cannot be accessed. The api management gateway is accepting the token as valid using the validate-jwt in the inbound policy and using the same b2c settings as in api, but then the call to the back end api fails with a 401 ie unauthenticated.

This is not an issue when using google apigee as the api gateway, The same token works and returns valid data. Please i need some help on this.