Try to use a local address instead of a public one.
Also, it’s not recommended to publish the dashboard to the internet without any protection - you exposing your private information.
It’s better to use this method: How to remote access the web dashboard - Storj Docs instead.
Multinode dashboard works well for me.
StorjNodeViewer for the local node works fine. But for remote nodes should I open some additional ports on rooter or there are some other settings?
Services exist to support this usecase (accessing lan web applications from anywhere) that don’t require opening any incoming ports nor tracking IP, port onocking, etc; instead managing access with some identity provider. The one I’m most familiar one is cloudflare zero trust. And it’s free for personal use. No need to reinvent the bicycle with ports, ssh, and other concoctions.