Alternate App Icons not working in test flight

I've been working on implementing alternate app icons for my iOS app, and everything works perfectly in debug builds on both the simulator and a physical device. However, when testing on TestFlight, I encounter the following error:

The requested operation couldn’t be completed because the feature is not supported.

Has anyone faced this issue before? Is there a specific TestFlight configuration or setup I might be missing to enable alternate app icon functionality?

Alternate App Icons not working in test flight
 
 
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