We have identified an issue when using NumberFormatter with the locale set to it_IT. Specifically, when formatting numbers with exactly four integer digits, the grouping separator is not applied: for example, the number is displayed as 4000,00 instead of the expected 4.000,00. This behavior occurs only with four-digit integers; for instance, 40.000,00 is formatted correctly. The issue appears to affect only iOS 18.4 and later versions.