Azure webjob Servicebus listener not working in SingletonInstance

[rajurh]

I am trying to use webjob with ServiceBusTrigger functionality where any message placed in a particular topic and subscription want to trigger webjob to execute certain functionality or business logic.

ServiceBusTrigger works perfectly where as soon as a message is placed in topic and subscription webjob is triggered.

Problem statement: If I place multiple message in Topic, WebJob is triggered with multi instance.

Requirement : I would like to do it in a singleton instance where message are processed one after another rather doing in multi instance. I tried placing a file in kudus with file name settings.job with content { "is_singleton": true } still its working in multi instance.

Also if I am trying to place message in number 100+ for a topic I am getting error with below information:
[12/13/2018 11:28:22 > 8d3718: INFO] MessageReceiver error (Action=Complete) : Microsoft.ServiceBus.Messaging.MessageLockLostException: The lock supplied is invalid. Either the lock expired, or the message has already been removed from the queue. TrackingId:d3acb4b4-41ed-43e9-a1d9-d64aa744044b_G6_B0, SystemTracker:staffingentitelementpocsb:topic:staffingentitlement95|EntitlementStaffing, Timestamp:2018-12-13T11:28:21 ---> System.ServiceModel.FaultException`1[System.ServiceModel.ExceptionDetail]: The lock supplied is invalid. Either the lock expired, or the message has already been removed from the queue. TrackingId:d3acb4b4-41ed-43e9-a1d9-d64aa744044b_G6_B0, SystemTracker:staffingentitelementpocsb:topic:staffingentitlement95|EntitlementStaffing, Timestamp:2018-12-13T11:28:21

Help on this will be much appreciated.