Thank you for providing the sample project. After examine it, it turns out that the data is returned correctly from the controller. The reason for the issue is that the numbers, that are used as IDs for the items are too big and the JSON parser cannot parse them correctly. You could ensure this by running some simple tests in your browser's console. Here is a small example
As a solution, you could use smaller numbers or a guid for the ID property.
I hope that this information was helpful for you. I wish you a great day!
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