On my Windows machine, I use following command to connnect to SAP DWC
hdbsql -u <USER> -p <PASSWORD> -n <HOST IP>:443 -e
I get this error
* -10709: Connection failed (RTE:[89013] Socket closed by peer {#### -> ####} (####:443))
My IP address is listed in the allowlist in SAP DWC
PS.: As I'm on Windows, I do not explicitly provide the trusted root certificate to the client.