Hi Henry,
I had a similar issue a couple of weeks ago .
Initially I was unable to log into Field maps with my Android device , I assumed this was due to the upgrade to version 11 . After a factory reset I was able to login, however was still unable to download an offline area and inconsistently received the message " Feature Tiling disabled".
Connecting from my home Wi-Fi with VPN and was able to connect and download offline areas for both hosted and enterprise feature classes. I can confirm that the issue was due to our IT dept changing security and whitelisting on our secure Wi-Fi .
Rhys Walsh from Esri provided me with the following documentation which may be of assistance:
When discussing with the Security/IT teams, the following documentation provides overall recommendations and guidance on domains to allow when whitelisting ArcGIS Online web traffic:
* Domain Requirements for ArcGIS Online -
https://downloads.esri.com/resources/enterprisegis/AGOL_Domain_Requirements.pdfIf the usage of wildcards when whitelisting domains is disallowed, a list of specific domains to allow can be found in the document below. As per the document, please note this may not be fully inclusive, as ArcGIS Online infrastructure does change over time.
* ArcGIS Online FQDN Requirements -
https://trust.arcgis.com/en/customer-documents/domains/Regards Bronwyn