The prepaid credits balance fetch now checks whether the amount field in the API response is a number before using it. If the field is absent (for example, on accounts or regions where the endpoint is not supported), the fetch returns null and records a not_supported telemetry event rather than passing undefined through to the balance display.
Evidence
guard added before ke("api_prepaid_balance_fetch") (search for "not_supported" in prepaid balance fetch context)
Strings lifted out of the shipped bundle, so the claim above can be checked against them.