Audi Radio Code

[needradiocodehelp]

I can't believe I'm reaching out for help with this—I'm usually the go-to for directing people to the right website to get their codes.
Here's the short version: I changed the battery and when I powered on my Audi Audio10 radio with RDS, it displayed the word "CODE." I found the code in the manual, tried inputting it, but the radio keeps showing "WAIT," indicating the code is wrong after three attempts.
I went to the Audi dealer, got the same code, but it didn't work. I even removed the radio, noted its model and serial number, and used www.radiocodehelp.com, which gave me a different code. However, the radio only allows four digits to be input, and the new code starts with a 6, making it impossible to enter.
I'm a bit stuck now because someone's coming to see the car later, and the radio isn't functioning. Any suggestions would be greatly appreciated.

[alpha omega]

would unplugging the radio and waiting a few hours(inconvenient)then trying it.regards

[Steve Q]

I wonder if the security system on the radio has failed?