In skincare discussions what you experienced is called “pilling” and it’s the result of putting on a lotion or skin product too soon after another one that was applied too thickly or didn’t have time to absorb fully. The balls are dead skin and the dried lotion or sunscreen that has gotten gummy and stuck to itself like eraser bits. Apply your sunscreen a little bit thinner and rub it in well and it shouldn’t continue to happen.
If you soaked your skin then that is just dead skin cells. Pilling happens on dry skin.
Lotion is composed of a water part that gets absorbed or evaporated and a fat or wax part that only absorbs into the very top layer of dead cells.