A flaky cere is completely normal in budgies it's nothing to worry about.
Ok, this is not entirely accurate.
A flaky cere can also be an indication of scaly mites, which needs to be treated with Ivermectin (or similar) by an avian vet.
Has your bird ever been to an avian vet?Thank you so much for informing me, as well as quelling my worry about his cere 💖 I feel so much more relieved knowing it's natural