Something is causing packet loss. This is why you're getting that lag. There are a lot of different variables at play so it's not something we'd be able to diagnose. Especially not when reports of this same issue are so few. Do you play any other online modes in NHL 26? If so, does this also happen in them?
Are your family members also gaming or are they mainly online streaming media and doing general internet use? Video is buffered so when there's a small amount of packet loss, it typically won't be noticed. A game like NHL requires a very stable connection so even the smallest amount of packet loss is going to be noticed. It's a lot more demanding than something like watching TV/movies.