Room temperature matters. If the jar is cold to the touch and the air is moving soy sets up fast on the sides and clings to the glass. That creates the classic tunnel after a couple of short sessions. Warm the playing field. Trim the wick and burn in a warmer draft free spot. If the wax has already built a ridge, use a foil topper or gently warm the sides with a hair dryer so the heat can catch up to the edges. Let it cool completely before moving it so the surface sets smooth. Next time, start in a calm warm area and give it that first full melt. After that, shorter sessions will behave better.
