I believe the system takes UCIs with or without dashes, so no problem there. Also I think the old ecas system (for paper) works with either UCI or the Application number.
This seems to be some kind of IT issue. Clearly they have multiple systems and possibly data transfer happens overnight and potentially there were some errors at that time. There was one other post in this forum where the applicant couldn't create an account for 6 months but the application was processing in the background, which is a relief.
The only place where having an account can make a real difference seems to be the headsup you get before the test or when the invite email goes missing. Hopefully you'll get the account working sooner than that. It's started working at random times for others like a week to two or sometimes a month after AOR,