Draytek Vigor 2865 with a 64GB USB storage plugged into it and formatted with FAT32. Every night I have a remote database backup take place and a copy is sent to my router over FTP and saved onto the USB drive. This has worked reasonably well for months, other than the occasional crash, but since upgrading to firmware 4.4.5.1 (and 4.4.5) it now crashes/reboots the Draytek every time the FTP process starts. I removed the USB and it was full of corrupt/empty folders with random characters in the name, so I formatted it and tried again last night but same things, the router just goes into a reboot loop until I remove the USB drive and the backup fails.

Anyone else having the same issue?

Check the various threads on problems with 4.4.5 and its successors on several routers. It appears that a 4.4.5.3 (yet to be released) may resolve the issues, at present only solution is to revert to whatever worked last for you.