Historic uploads failing silently on emoncms.org, not on local server

I’m evaluating EmonCMS as a way to display various meter-capture data, and have a few weeks’ worth of 15-minute interval consumption data to upload so I can play with the visualization tools. I’ve used this script to successfully upload historical data to emonCMS v9.7.9 running locally.

However, when I attempt to upload to EmonCMS.org (even with chunks as small as 50 data points), the server responds with “ok”, but nothing is actually uploaded. My input/view/ page still says “No inputs created”. Same behaviour when I manually construct a …/bulk.json GET url using a data= argument like this one.

Any idea why this is failing silently? Is my upload broken? Is my account somehow misconfigured? Am I doing something I shouldn’t be trying to doing?