It’s memory related not storage related, please see Memory Notifications
Please navigate to Displays page → Edit display → Advanced tab → Reconfigure XMR & Save (you might want to restart Xibo on your device after making this change) - assuming that XMR is correctly configured, it should be fine after this action.
It could imply that it did download the file twice, or rather that the first download failed for some reason (perhaps was incomplete) and then it did download it again - assuming that it is downloaded correctly now, if you’d clear the display cache (just edit&save) next time it connects to the CMS (collection interval) it should change the status of that file to checkmark.