(For reference, creating a support ticket with NVIDIA Enterprise Support would probably be the best way to get an assured response to these types of issues- an email to mailto://EnterpriseSupport@nvidia.com would be a quick way to create a new ticket.)
Indeed, that device node isn’t present in DGX OS 4.0.x with the 410 series Tesla driver. Upgrading to DGX OS 4.1.x with the 418 series Tesla driver resolves the issue. For example, upgrading from DGX OS 4.0.7 (what you have now) to DGX OS 4.1.0 with the instructions in https://docs.nvidia.com/dgx/pdf/DGX-OS-server-4.1-relnotes-update-guide.pdf yields: