Next, they suggested I try registering with an alternative country, so I chose Hong Kong. After attempting to register with a different country, my account was successfully created. The support agent mentioned that they would update the information in their system and monitor the issue for the future. They allowed me to activate and proceed with my account.
This can help you to create your account successfully now, but it can become your problem with KYC later.
I think you have to contact the support agent, and ask about it, as well as asking the staff to make this note on your account for you, like you created this account with Hong Kong as nationality, because of their platform issue in registration. The note must have information from your true nationality, that will be used when you need to do KYC, if the team request it.