Video Uploads Via FTP Fail and Start Over

My uploads via FTP used to work just fine, but for the past few weeks they've been failing randomly. The upload will get close to finishing, and then just automatically start over. It does this with seemingly any videos I try to upload. And it's always a different point at which the upload fails and then starts over. Watching it, sometimes it'll get to 99% complete, then fail; sometimes it's 80%, sometimes 60%; sometimes it fails even earlier, but usually it's closer to the end of the upload. It really is just random every time.

I'm using Filezilla and am using the latest version. On the rarest of occasions the uploads will actually finish and work properly. I also use Filezilla to upload videos to other stock sites and do not have problems.

Anyone run into this?

Sometimes when it fails Filezilla returned this error:

Error:        File transfer aborted by user after transferring 561,097,104 bytes in 1610 seconds

(I never abort the transfers. They fail and restarted automatically)

And other times when they fail Filezilla returns this error:

Error:        Connection closed by server

Error:        File transfer failed after transferring 1,507,196,616 bytes in 3600 seconds

Thanks in advance for any help!!