Odd harmonics / sound

Got my mom a mk4 kit for Christmas and has worked really well so far (43 days total print time). Had a few issues here and there but nothing major, i.e. clogged nozzle. So a new odd noise just started on this print and it has me a bit perplexed. I am guessing it might be due to speed, because from the screen I slowed print speed from 100% to 90% and the noise is still present but it sounds lower/quieter (same as when it slows for external perimeters). The highlighted red sections are where the noise occurs on both models (same model just differently sized). Settings - Generic PETG (Overture) 240 nozzle / 70 bed .4mm nozzle / .2mm layer height @ mk4 speed profile Link to video - https://youtu.be/PpcfQmqUrwk?si=mRwfqdMLGWl6MtEG