Have you done an upload speed test to see what the current available bandwidth is?  

253.2 mbps

Yeesh...ok only thing maybe left to check is whether there is a rate limiter in your FTP client (also if you are using passive FTP turn that off).  If not, could just be a slow day.

Hi Chris, 

Welcome to Box Community and glad to help!

Let me open a new ticket and a member of our team will be in touch shortly. We'll contact you via email and please keep an eye out. 

Thanks for posting!