Hm, same things. Neither the private electrum server to nostr:npub1tr4dstaptd2sp98h7hlysp8qle6mw7wmauhfkgz3rmxdd8ndprusnw2y5g's node, nor the public server over Tor proxy, seem to work.

If Sparrow has built-in Tor, is there a way to use that natively to connect to a public node (rather than needing the Tor proxy)? 

I.e. is it possible to connect, say, to the electrum.bitaroo.net node with sparrow’s Tor feature, and not share my IP address etc with Bitaroo?

Only other thing I can think of is that my laptop has an always-on VPN, but that’s never caused any problems before today so it shouldn’t be the issue…