@Ethan Metcalf, Thanks for posting in Q&A.
From your description, I know you have deployed auto update profile on kiosk Android device but failed to auto-update.
Based on my research, Kiosk deactivates the system apps responsible for updates, you need to approve the packages as android system apps in order to have the O.S. updated and here are two example apps you can add
com.sec.android.soagent
com.wssyncmldm
Or you can try to add another one.
com.google.android.configupdater
https://www.reddit.com/r/Intune/comments/x7zo1f/android_kiosk_device_not_updating_os_while_on_mhs/
Non-official, just for reference.
Hope it will help.
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