On your iOS device, trigger a sysdiagnose using the appropriate key combo:
Volume Up + Volume Down + Side Button (hold for ~1.5s).
Wait until the screen flashes and you hear a chime. The file will be generated in the background (this may take 30–60 seconds).
Open the Settings app and navigate to:
Settings › Privacy & Security › Analytics and Improvements › Analytics Data
Look for a file starting with sysdiagnose_. Tap the file, then hit Share in the top right.
In the Share Sheet, select 'More' then tap:
"SysDiagnose Upload"
This will send the file to our secure server for analysis.