In the past when I ran Sparrow Wallet from the command line, or at all really, I had issues getting it to connect to anything. There was no firewall running. With a Bitcoin node, the connection would not get established, and the same thing happened with public Electrum servers but that must have a more obscure reason.

I had never tried connecting a private server to it, though.

So Sparrow is a pretty good wallet, once you get the connection working first.