Different markets. The price that went negative was for immediate delivery of gas (spot market), while utilities buy their energy way before it's actually delivered (futures market). The price on the spot market went briefly negative because it's unseasonably warm in Europe right now (so less gas usage for heating), and all the storage is nearly full. The price on the futures market is still high, because once it gets cold demand will pick way up and outpace supply.
An interesting sidenote is that storage being full significantly increases volatility in the market: in the usual situation, a storage facility would buy up all the surplus gas on the spot market at a cheap but probably non-negative price, store it, and sell it on the futures market for a higher price. This stabilizes the market, and creates some constraints on market prices. Now that storage is full, they can't do that, and prices can fluctuate much more.
They’re trying to cut off Russian supply and being threatened of being cut off. Russian supply is being replaced with American gas. But this is new, it was warm, there was too much gas in places. It happens. It’s good news really.