I have a problem trying to connect to a MSSQL Server hosted in the same host to Node-Red.
Node MSSQL outputs this error: ConnectionError: Failed to connect to 127.0.0.1:undefined in 15000ms
You server doesnt look quite right. I realise it is a sql express but still, it doesnt look right.
So, regarding SQL instances: they don't (usually) appear on port 1433 like full installations. If you check the SQL logs you should find the correct port & you can use that in the config.