It looks like this was an issue with some data coming through in unexpected ways. Certain runs have fields which triggered an error, and so if a run formatted like that happened to be a part of the list of runs in the import request than the whole thing triggered an error. That was why setting a minimum import date fixed it in some cases, but not others, because the minimum import date may have resulted in filtering out some of those runs.
Unfortunately none of the accounts we tested with before going to beta had runs formatted like that, so we weren’t able to catch it earlier.
We rolled out a fix this afternoon, and also included some additional logging to debug future issues. I’m expecting there will be plenty, since it looks the data coming through the API might have idiosyncrasies depending on the original source.
So, please try syncing again. If you encounter an issue, try unlinking and relinking your account, and if the issue persists start a new topic as necessary.
Thanks for your patience. 