Home automation with “Get Contents of URL” fails after OS 27 update, but manual testing works

After updating to OS 27, my Apple Home automations converted to Shortcuts and containing “Get Contents of URL” no longer produce the expected result when triggered automatically. The same automations worked before the update.

However, opening the exact same automation in the Home app and tapping “Test This Automation” works: the URL request completes and the receiving service gets the expected data.

Steps to reproduce in my setup:

1. Create a Home automation triggered by an accessory or switch.

2. Convert the automation to a Shortcut.

3. Include “Get Contents of URL” to send a request to a local service.

4. Save the automation and trigger it through the accessory.

5. Compare the result with manually selecting “Test This Automation” in the Home app.

Expected result:

The URL request should complete during automatic execution, just as it does during manual testing.

Actual result:

Automatic execution does not produce the expected result at the receiving service, while manual testing succeeds.

For context, my setup uses a HomePod/HomePod mini as the Home Hub. The Shortcut reads a HomePod temperature/humidity value and sends it to a local Home Assistant server. I have observed the same behavior with both a Home Assistant-exposed switch and a physical HomeKit accessory as the trigger.

I have not isolated the exact failing step, so I cannot tell whether the automation fails to start or stops during execution. The key issue is the difference between automatic execution and manual testing of the same Home automation containing “Get Contents of URL.”

Has anyone else experienced this after updating to OS 27? Have you found a workaround?