Error "[Error: Redis connection to localhost:6381 failed - getaddrinfo ENOTFOUND]" seems to point to an address resolution issue.
A simple proposal was therefore to use 127.0.0.1 instead of localhost to bypass the call to getaddrinfo, and the associated DNS query which can fail.
The result with 127.0.0.1 was slightly different: still an error, but the message was now ECONNREFUSED meaning that the remote Redis server was probably not listening to the provided port - or perhaps the connection timeout was set too low.