Hi There,
Thank you for asking this question on the Microsoft Q&A Platform.
The most probable reason of this warning could be 'Shutdown an endpoint while busy receiving/processing.'
We would suggest to please check the below discussion where it was identified the issue. This could help you to troubleshoot your issue.
https://github.com/Particular/NServiceBus.AzureServiceBus/issues/337
Regards,
Kamlesh Kumar
BizTalk Techie
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