Sender ID registration for Singapore always fails

I started the process of registering a Sender ID for Singapore to be marked as SPAM or SCAM SMS in future. I followed the steps of the article: https://docs.aws.amazon.com/pinpoint/latest/userguide/channels-sms-senderid-singapore.html and I entered the company information exactly as it is on our official and valid ACRA document. I checked it a couple of times, but everytime the status immediatly comes back as "requires updates". I am out of ideas what can be wrong, so I need assistance. Anybody else experienced the same problem?

Thanks, Christoph