Cannot send events from Azure App Services (ASP.Net)

I have two web applications, both using .Net Framework 4.6.1.

One is a WebForms app, the other is an MVC5 app.

Both applications are able to log events to my Sentry account when running them in IIS locally.

Both applications are able to log events to my Sentry account when running them in IIS on and Azure Windows Server VM.

When deploying them to Azure App Services, neither application logs any events in Sentry. I’ve tested this in the MVC app by creating a route that explicitly logs an event using SentrySDK and the event never appears in Sentry.

The code running in the app services is identical to that running in IIS.

Have I missed something?