The full solution is below, with a short explanation for each group. To avoid spoilers, play the puzzle or open the hints page before reading the answer panels.
BOWLING, POOL, TRACK, and ROAD all fit the category "Things with lanes". Movement is organized into lanes. The shared link accounts for all four words, which is why the remaining board words should be tested against a different rule.
Category
Ocean words
WAVE / TIDE / REEF / KELP
WAVE, TIDE, REEF, and KELP all fit the category "Ocean words". They belong near salt water. The shared link accounts for all four words, which is why the remaining board words should be tested against a different rule.
Category
Kitchen verbs
DICE / WHISK / FOLD / SEAR
DICE, WHISK, FOLD, and SEAR all fit the category "Kitchen verbs". These are actions from a recipe. The shared link accounts for all four words, which is why the remaining board words should be tested against a different rule.
Category
Baking staples
YEAST / SUGAR / BUTTER / FLOUR
YEAST, SUGAR, BUTTER, and FLOUR all fit the category "Baking staples". A bakery keeps these close. The shared link accounts for all four words, which is why the remaining board words should be tested against a different rule.