Cloud Deployment UI modal dialogue hangs during deployments

[jattwood]

Issue description

This is starting to happen more and more. Like all great problems, it's intermittent. So I am assuming this is network traffic related (just a theory).

We initiate a deployment from remote development to live. The UI will hang on the initial startup routine "Loading activity data" for an extended period like this:

The API calls that are happening behind the scenes report a small JSON response: {"Message": "Forbidden"} response here:

Doing a hard reload resolves the issue and the deploy carries on to completion. But... sometimes not.

Again intermittently, the UI will hang during the extraction process as well. You can see here from the CPU insights that the deploy completes, yet the activity running indicator is still present:

Finally, a hard reload brings everything back to normal. In both cases, {"Message": "Forbidden"} is returned from the cloud API endpoints.