Paul,
We are now working on upload procedure fixes and improvements that should help in your case. It will take approximately two weeks to implement, test and release everything that is planned. We will notify you about the release.
Until then we can recommend you to delete this project from the cloud, increase the `main/cloud/max_retries` tweak value, decrease the `main/cloud/part_size_mb` tweak value, and try to upload the project again.
If it will not work, try once again with increased `main/cloud/max_retries` value and reduced `main/cloud/part_size_mb` value.
If nothing helps - please wait until the new release.