Same here. I was just in MUFG in Tokyo, they say it's not up to them. My katakana name was wrong so I matched it to the wrong one MUFG has on file. The registration went through, but there's still an orange exclamation mark....
After a few hours it's all ok. Apparently there's a time lag so even after you succeed to link the account it will say it's not connecting for a couple of hours. And yes, my katakana name was the problem
