Debugging Bad Request: /graphql "POST /graphql HTTP/1.1" 400 371

[jmsuresh]

I am using graphene in the Django backend. The frontend uses Apollo library to make queries and mutations.
In one of the mutation, the request fails as below in the backend terminal:

Bad Request: /graphql
[03/Dec/2021 06:13:27] "POST /graphql HTTP/1.1" 400 371

The Apollo client's error messages were also not very helpful:

index.js?6e99:29 Uncaught (in promise) Error: Response not successful: Received status code 400
    at new ApolloError (index.js?6e99:29)
    at Object.error (QueryManager.js?1d9d:137)
    at notifySubscription (module.js?7b50:137)
    at onNotify (module.js?7b50:176)
    at SubscriptionObserver.error (module.js?7b50:229)
    at Object.eval [as error] (asyncMap.js?a45e:32)
    at notifySubscription (module.js?7b50:137)
    at onNotify (module.js?7b50:176)
    at SubscriptionObserver.error (module.js?7b50:229)
    at eval (iteration.js?ac54:4)

I am wondering if there are any settings I should enable so that graphene prints some more information to enable debugging.
Please share any useful information.