DownloadDependenciesAsync does not complete

var loadDependencies = Addressables.DownloadDependenciesAsync(keys,Addressables.MergeMode.Union, false)

does not seem to be completing and halts at 0.9x % most of the time. It neither triggers the Completed callback or sets the IsDone flag. How do we fix this?

Assuming it is at 0.98%, on restarting it by calling the above function, it seems to resume at the same percent and stays stuck again - this is Unity 2019.2.15f1