Timer and authorization challenged during postback

I have a site that using windows authentication and a custom role provider and is running on Azure environment.  One of my pages has a timer that will run every minute.  I have noticed this page produces a lot of 401.2 and 401.1 entries in the server logs.  When I am actively using the page and it is posting back authorization works fine and the responses come back with 200.  When I stop using the page and the ansync postback starts running every minute from the timer, for some reason authorization is challenged.  I'm not sure what to start looking at for root cause.

Here are some of the entries from the log file.  13:31:06 is my last action before I let the timer do its thing.  The timer just performs a database hit and posts back to the same page.

My cookie is the same for all entries.  The roles and session are sent over.  Cookies have 10 minute sliding expiration and Session has 30 minute sliding expiration so both are still valid when the timer starts posting back.

SMMSADIDENTITY=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;+SMMSADCHALLENGE=NTC_CHALLENGE_DONE;+ARRAffinity=2b3382e259bcded79cf2fe0b059efd2c22d485b467015b81ad8ee3ca7f1cb9a6;+ASP.NET_SessionId=csvynkt2jrouemr55zldlmpk;+.ASPROLES=AAEAAAD_____AQAAAAAAAAAMAgAAAE1TeXN0ZW0uV2ViLCBWZXJzaW9uPTQuMC4wLjAsIEN1bHR1cmU9bmV1dHJhbCwgUHVibGljS2V5VG9rZW49YjAzZjVmN2YxMWQ1MGEzYQUBAAAAIVN5c3RlbS5XZWIuU2VjdXJpdHkuUm9sZVByaW5jaXBhbAgAAAAIX1ZlcnNpb24LX0V4cGlyZURhdGUKX0lzc3VlRGF0ZQlfSWRlbnRpdHkNX1Byb3ZpZGVyTmFtZQlfVXNlcm5hbWURX0lzUm9sZUxpc3RDYWNoZWQJX0FsbFJvbGVzAAAAAgEBAAEIDQ0BAgAAAAEAAACm-Cq_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

The web.config has the following entries. 

<system.web>

<authorization>

<allowroles ="ADM,QUE_MAN,QUE_SUP,QUE_USR" />

<denyusers ="*"/>

</authorization>

</system.web>