Solution
Error -5580997 is equivalent to Hex 0xFFAAD73B. This error means the SSH server's identity is unknown and could not be read. No previous connection attempt to this server is recorded. No server fingerprint could be identified from the connection logs.
In other words, LabVIEW does not trust the target system. In order to solve this issue, you need to manually connect via SSH (tools such as Putty or MobaXterm are recommended) to the target system and ensure that the host key is trusted. By doing this once, LabVIEW will now trust the system and will be able to connect.