I assume you have tried all the usual things? Uninstall and reinstall, cleaning up your computer, uninstall bloatware, removing other unnecessary apps/programs which launch at start up, etc?

You don't have to use the NordVPN app if it is causing you problems. NordVPN will work with other VPN software such as OpenVPN or WireGuard. It will take a little bit more time to set up, but their website has instructions and pre-made configuration files for you to use: https://support.nordvpn.com/General-info/1047408082/What-is-OpenVPN.htm. I actually prefer to use these because they give you more control and customization options than most individual VPN apps or software.