Oh... Yes that's something different. Hope you can make difference between your first and last screenshot. Despite of similar values the meaning is completely different! My net is significantly slower, but Dropbox application successfully fill up all my bandwidth (I just made a test). Despite my slower network speed Dropbox speed is not many times, but many orders faster.
I don't know. 🙄 This might be bug in the current version (most probably) or some connection trouble to the Dropbox servers. Try investigate network path throughput to content.dropboxapi.com