An unexpected value could not be normalized

Never experienced this... Did you double check your custom code? Can you reproduce this on a clean install?

Hi, I am seeing also this error when I upgraded commerce to 2.36 from 2.33. As I checked I think this causing the issue, the addition of https://git.drupalcode.org/project/commerce/-/blob/8.x-2.36/modules/log/...

I am also seeing this error with REST export views for Commerce Log entities, if the view results contain any Log entity which has a template that expects Price parameters. Since a typical checkout flow implies an automatically-created payment after completion, the order's activity log will have an entry for the payment with its amount, and so you can't expose the activity log of non-draft orders.

I had the same thing happen to me recently. Thanks to the comment by @ts.ag, I remembered seeing something about logging on the Order settings page. When I changed the setting to "Prevent the save and throw an exception that may cause a fatal error," the problem disappeared.