Having same problem with iPadOS 16.1 and makes RD Client unusable at all. It happens regardless of what keyboard I'm using. I tried iPadOS on-screen keyboard, magic keyboard, and separate bluetooth keyboard (a Logitech one) all shows same symptom. I also tried windows 10 21H1 and 11 22H2 the bug happens both of windows versions.
RD client problem with typing Korean language

Solkeun Yi
16
Reputation points
Precondition: iOS 16.0 / 16.1
RD client 10.4.5
Issue: When I type a Korean consonant and a vowel, several duplicate consonants are typed and it happens repeatedly. For example, when typing'가‘ which consists of 'ㄱ’ and 'ㅏ‘, it is shown as 'ㄱㄱㄱㄱㄱ가’. It doesn't happen when I type just consonants or vowels like 'ㄱㄱㄱㄱ‘ or 'ㅏㅏㅏㅏ’. It seems to be a matter of merging consonants and vowels. No problem with English.