Since Mikrotik supported IKEv2 to ISP I am using NordVPN and I always was very pleased with it. Since the implemented a separate username and password for router implementations things got sometimes wonky.
The latest is that it appears that some sites become unreachable through the VPN and the latest are duckduckgo.com and security.nl and if someone can also test it then I can put this to them. I tested myself and when I use and different VPN provider all goes well.
On my PC I have the client from them and when I want connect to two sites they don't show using WireGuard. This is punching a hole through the firewall of the router so the router is working fine.
It could of course be the case that those sites are blocking NordVPN but look unlikely to me.