Probable cause and solution

For me the problem was related to GRPC and its environment variables. Look at the first two ENV variable rows here: https://grpc.github.io/grpc/cpp/md_doc_environment_variables.html

As stated:

grpc_proxy, https_proxy, http_proxy The URI of the proxy to use for
HTTP CONNECT support. These variables are checked in order, and the
first one that has a value is used.

no_grpc_proxy, no_proxy A comma separated list of hostnames to connect
to without using a proxy even if a proxy is set. These variables are
checked in order, and the first one that has a value is used.

During examination of the logs of the application, it has been discovered that HTTPS_PROXY and HTTP_PROXY variables were causing the GRPC connection to fail with the said cryptic error.

Solution: Unset the offending variables in the process before initiating a GRPC connection.