Using cURL with NordVPN SOCKS5 proxy

I am trying to use the cURL utility to fetch a web page through a NordVPN SOCKS5 proxy, but not having any luck. I would expect the following command line to work.

curl -v -x "socks5://:@se.socks.nordhold.net:1080" -4 http://google.com 

However, this returns the following.

*   Trying 185.236.42.56:1080...
* SOCKS5 connect to IPv6 2a00:1450:4009:815::200e:80 (locally resolved)
* Can't complete SOCKS5 connection to google.com. (4)
* Closing connection 0
curl: (97) Can't complete SOCKS5 connection to google.com. (4)

Is there some special configuration I need for cURL to connect to a SOCKS5 proxy operated by NordVPN? The customer support were able to tell me that > We’ve changed the way for users to connect to socks5 to reduce the chances for socks5 from being used for malicious purposes such as web scans/proxying/credential stuffing attacks. ... but they could not offer any suggestions on how to use cURL. All I can say is that some other software seems to be able to use NordVPN SOCKS5 proxies without issue.