There has been a bit of buzz recently surrounding the 3DS it has become apparent that Nintendo is targeting consoles that utilize homebrew and CFW. It appears to be a permanent ban and the exact method of detection has not been made public yet.
Perhaps the safest route if you are not already banned is to disconnect from the internet till new information is brought forth.
Source ( I’ve seen this a few places now, but GBATemp will probably have the most reports. ) https://gbatemp.net/threads/regarding-the-recent-3ds-banwave.471781/
For more information and help, visit the forum thread by visiting the link below:
Nintendo Banning 3DS Consoles