@Bambos A timeout error means that the host did not reply in the expected delay, which, if I'm remembering correctly is 5 minutes. I suspect a problem on your host but we will take a look further on your support ticket.

@olivierlambert XO and XO Proxy are using the same code and the same backup workers to run backup jobs. If there are differences in perf, IMHO, they come from the appliances themselves and/or their networks. Keep in mind that data flows from the host, via XO or XO proxy, to the remote storage. Maybe the proxy is further from the host and/or the remote regarding the network?