Starter code import stalling (again)

The starter code import process is stalling at 0% progress (no green bar). Curiously this is on an assignment with “Import starter code using a template repository” checked, so it is not the old latency problem with the “source importer” method. The same assignment worked fine this morning (around 8:30 am PDT) but students saw it stall in the afternoon (2:30 PDT).

Is anyone else seeing this problem? Is there a workaround?