Try adding Application Insights to the app. You should see errors on startup of your application.
I would also take a look at your startup code to see if you are writing to disk anywhere during configuration or app.start. This might be the case if you are using AAD in any capacity.
You can also hit up the KUDU console by targetting https://sitename.scm.azurewebsites.net . You will be able to navigate in the debugging console to see the RAW logs from IIS. That might shed some light into the situation. See KUDU for more info.
与恶龙缠斗过久,自身亦成为恶龙;凝视深渊过久,深渊将回以凝视…