SSD VPS (sometimes labeled as SSD Cloud VPS) doesn't have any DDoS protection which means that high network loads may be mistaken for a DDoS attach and thus the bandwidth is dropped. This happens at the operator level so there's nothing we can do about it. You may be able to configure bandwidth limitations in your firewall to get a more balanced flow.
The best advice however would be to get a Compute VPS instead, those plans has a better network infrastructure by default and you can add additional dedicated DDoS protection on them as well with hourly billing.
