The Republic of China flag emoji has disappeared from Apple
iPhone’s keyboard for Hong Kong and Macau users. The change
happened for users who updated their phones to the latest
Updating iPhones to iOS 13.1.1 or above caused the flag emoji to
disappear from the emoji keyboard. The flag, commonly used by
users to denote Taiwan, can still be displayed by typing “Taiwan”
in English, and choosing the flag in prediction candidates.
This is either a bug on Apple’s part, or kowtowing to China.