Upon running Windows Update KB4580979, .Net 4.7.2 projects that have the SessionStateSection.Cookiless Property set to AutoDetect no longer functions as expected.
Previously, a browser that blocked cookies would be redirected to the same page with the querystring /default.aspx?AspxAutoDetectCookieSupport=1 and upon the system detecting that cookies were not supported it would redirect again to a cookiless session URL e.g. /(X(1)S(adl04pietheradyfawfaqlym))/default.aspx?AspxAutoDetectCookieSupport=1
Since the update, a browser would continously be redirected to /default.aspx?AspxAutoDetectCookieSupport=1 until the redirects exceeded the maximum redirects.
Relevant Web.config section:
<sessionState cookieless="AutoDetect" />
Windows Server 2019 DataCenter Version 1809
OS Build 17763.1369