I've gotten a repro of that issue on an A9 IPad (happened to be on IOS 14.x too, but deemed not relevant), something silly to do with Metal Language versions that was easily fixed. A new build that also fixes the UI issues others have reported is on its way out, please email me at jacob@vertigo.ai if you want beta access via Testflight. Should be GA within 1-2 days.
I haven't upgraded to iOS 15 though, I'm on 14.4, maybe that's the issue?