Your FTP is guaranteed to have changed (it's never static). You need to test again. Any other statements are guesses.

Just get recovered and do a real test again. If you want to test on the trainer again, that's fine, but you should start working towards a standard test.

FWIW: I don't really test FTP any more. I just know how I'm doing on certain threshold workouts, and spot check with an occasional 20-minute effort. That's enough for me to set zones/interval targets, and enough for me to track performance and training effectiveness. I'd recommend you do the testing while you're getting started in the power stuff though.