Due to the nature of soy/coconut wax, lumpy and bumpy tops after your first burn are common. The good news is that it’s 100% natural and will not affect how your candle burns. Just relight your candle and allow for a full melt pool to form.
Candles start to tunnel when a full melt pool is not reached before you blow out your candle. When lighting your candle, allow the wax to melt long enough to have the wax melted in an even layer, edge to edge.