Not all of the hik-connect servers will respond to echo requests (ping). This doesn't mean they are unavailable. Hik-connect predominately uses Amazon Web Services and some of the servers will reject echo requests. The IP was resolved in the capture below but the server refused to reply to my ping.
View attachment 3196
This should not effect the camera's link to litedev.eu.hik-connect.com as the port/protocol are completely different.
View attachment 3197
In your 4th screen capture it looks like Hik-connect sees the device. What happens when you try add it?