this error happen from 18:30 PST to 3:30 PST
I can support this observation. Last Friday I got very good transfer rates (15 simultaneous transfers, ~10 MB/s overall) in the afternoon. Now this Monday morning before 10h30 UTC the rate was extremely poor (few kB/s with 5 transfers, many throttled requests), but it seems to have “lifted off” at around 10h45 UTC. I am now (11h UTC) getting very few “activityLimitReached: throttledRequest” notices.
Note: I don’t use the --user-agent flag nor an own AppId. I may not need to try it if sending big files in the UTC afternoon works reliably.
This said, I observe something a bit odd: in the progress block, for each file the ratio of transferred data for each file quickly rises up to 100%, then the file transfer rate drops, but my network load monitor still shows high outgoing rate. E.g. all 5 currently transferred files are at 100%, show a file transfer rate around 10-20 kB/s, totalling ~100 kB/s, but the monitor says ~1-2 MB/s, which is a substantial difference! (The monitor does display MB/s and not Mb/s).