External Microphone cutting out when singing high notes in GarageBand

I'm using the latest version of GarageBand on my 24-inch, M1, 2021 iMac and I'm using a Shure SM7B microphone with a Focusrite Audio Interface. I'm a professional singer, and I know how to adjust my voice to different microphones/programs. I've never had this problem until the last couple of months. I thought that it would just go away, but it hasn't.

When I go to sing a high note at a louder volume, GarageBand registers the audio, and then quickly cuts out in the middle of the note being sung. In this example, I'm singing an octave jump. You can see the wider, more condensed chunk is the lower note. Then when I sing the higher note, it registers it, and then cuts out. The little piece of audio you see after that is an s that is at the end of the word I'm singing.

I just don't know what to do. I've tried turning off Feedback Protection, Noise Gate, tried various configurations with EQ in GarageBand and on my audio interface. I just don't know what to do anymore. Has anyone had this problem? Can anyone help me?