I downloaded the file again, just in case I had a bad download like @TheSayaMan
Installation went through without a hitch. Rebooted into TWRP and could not see my folders again.
I plugged in a USB Drive and reinstalled Magisk from the USB and then rebooted back into OOS13.
Everything except Decrypting is working.
Is there anything you need from my Oneplus 9 Pro that can help you ??
I just looked up the encryption on Android 13 from source.android.com,
it seems that Android 12 and below can use Full Disk/File encryption,
but Android 13 can only use File encryption.
I don't know if this helps or not.