This is completely normal and not a product defect. The solar mat is rolled up to save space for shipping - after unpacking, it needs some time to straighten out completely. Heat supports this process, especially direct sunlight. If it is still cool outside, smoothing can be delayed - even when the sun is shining. Cold ambient temperatures or cold pool water can also slow down the relaxation of the material.

Advice: Lay the solar mat flat and unfilled in the sun. As the temperature rises, it will gradually smooth itself out.