Hi! We are experiencing the same issue, long response from app.powerbi.com, sometimes no response - error 503 .
Tls 1.2 enabled, and worked good until yesterday.
Region West Europe
General Information Service Bus Namespace : WABI-WEST-EUROPE-relay23.servicebus.windows.net Host Name : ns-sb2-prod-am3-003.cloudapp.net Host IP Address : 220.127.116.11 Overall Results : 16/16 tests succeeded.
Note: If one or more tests failed, contact your network administrator to open the ports for the required servers.