Over the Islanders' last two games, they've put in just one goal. It's hard to win hockey games with that few goals even in a Barry Trotz system. Despite putting up just one goal, it's not like the Isles aren't getting their chances.
According to Natural Stat Trick, the Isles had 12 high danger chances for against the Devils and seven against the Maple Leafs. Of those 19 overall chances, they've converted on precisely zero of them.
Yes, you're not going to capitalize on every high danger chance I understand that but when you have just four high danger goals in your last five games while allowing eight it's a recipe to go 2-3 any day of the week.