Player Hangs at "Importing Playlists" Screen When Importing rekordbox Library

I have two brand new SC6000 Prime. When I connect my rekordbox-made USB sticks to the player and Import, it hangs indefinitely at Importing Playlists. I can Abort, then see that nothing was imported at all. Nothing can be loaded or played.

Player is on Firmware version 1.5.3, the newest. After power cycling the unit multiple times and trying again - no change.

The USB drives are Patriot Rage Elite 512 GB. They both work on all computers and Pioneer DJ equipment I’ve ever tried them on. They’re not corrupted. The SC6000 will import from neither. My old Sandisk 128 GB USB drive can be imported successfully and very quickly.

Denon, do you know why this doesn’t work? Will there be a fix for this coming soon? I would dearly like to avoid returning the SC6000’s for a refund!