VMExtensionProvisioningError deploying VE from Azure ARM template

I've been trying to use the F5 provided Azure ARM template here (BIG-IP VE in Azure - 3 NICs, PAYG, Existing Network). Everything deploys without issue, except the VM itself. I keep getting a VMExtensionProvisioningError "VM has reported a failure when processing extension 'start'. Error message: \"Enable failed: processing file downloads failed: failed to download file[0]: failed to download file: http request failed: Get [REDACTED] dial tcp: i/o timeout\"\r\n\r\nMore information on troubleshooting is available at https://aka.ms/VMExtensionCSELinuxTroubleshoot" I've verified that the NSGs have outbound access to the Internet.