[sandworm101]

That is another hair to split, between "registered" at time of infringement and "registered" at time of lawsuit.

You need to register prior to bringing a claim. That isn't a big deal and can be done easily after any alleged infringement. But to get the attorney fees you need to have registered before the infringement occurred, something you cannot fix after you decision to sue.

Then to split hairs yet again, was the work registered at the time it was copied by the AI, or are you suing over infringement that occurred after a late registration? Are you claiming it was registered when the AI was trained on it, or are you claiming registration during the work's subsequent use by the AI after the training process? Maybe you can get attorney fees despite late registration if you can prove ongoing infringement after the pre-registration training process.