Because ALL of your particles, most likely, covered with the hydrophobic paraffin wax and they stick to each other. You can prevent it if you use a certain surfactant to emulsify a small wax particles and/or use a nonionic emulsifier
At the optimal concentration of EGMS, emulsion polymerization of EGMS occurs. In this process, EGMS acts as a surfactant (stabilizer) of the EGMS polymer emulsion. As the concentration increases, the emulsion disappears due to the high concentration of EGMS polymer.