Same issue here, also Pixel7.
Even on some older devices running Android 10, I get warnings about compatibility but in practice it works fine. If you read other posts here, it's clear Line6 have abandoned Amplifi devices some time ago. If they didn't even bother to update the app for Android 10 they will surely not make it work for Android 13. I'm just keeping an old device dedicated to controlling my Amplifi amp for now :-(.