Major iPhone HDR Issue

Issue: Photos taken using the iPhone camera with HDR on only display the dynamic range when viewed within the native Photos app. Loading, uploading, exporting, air-dropping, or otherwise sharing the HDR photo elsewhere results in a flat and unremarkable photo stripped from HDR.

Steps to recreate:

1. Take a photo with HDR.
2. Open the photo in the Photos app (make sure Settings > Photos > View Full HDR is on). Observe that the photo displays a full high dynamic range with luminosity and exposure as expected.
3. Load the photo in Instagram, Facebook, or any other app, or share the photo via AirDrop or USB to a computer, such as a Mac.
4. Observe that the photo no longers shows the dynamic range it displays when viewed in the Photos app. It now looks flat and unremarkable.

The same happens when taking a screenshot of any HDR photo. The screenshoot is flat compared to the original photo.

It appears that the native Photos app automatically adjusts the iPhone display to show the complete dynamic range. However, the HDR is useless if the user is unable to display any HDR photo as HDR outside of the Photos app.

Using an iPhone XS.

Expected: An HDR photo should display as HDR in third-party applications.

Does anyone know how an HDR photo can be preserved and displayed as HDR elsewhere, particularly in Instagram?