There are far easier ways to compromise your own privacy, to log and track and re-sell your online activities including your browsing history, and to do so while using negligible added security due to widespread knowledge of the tunnel credentials.
That in general.
One reason you might be getting blocked here is if your existing and actually-encrypted connections are getting intercepted and decrypted and scanned and then re-encrypted within the VPN connection, too. While there might be other reasons for the failure here (such as fraud detection or password-theft detection), various servers are now detecting SSL/TLS interception, and SSL/TLS itself is being updated to make these sorts of connection interception operations more difficult.
Specifically with NordVPN:
https://www.theverge.com/2019/10/21/20925065/nordvpn-server-breach-vpn-traffic-exposed-encryption
https://thehackernews.com/2019/10/nordvpn-data-breach.html
Given the wide knowledge of the VPN credentials, I wouldn’t expect all that much added security over the SSL/TLS connections already in use for your secure connections.