You might not be cleaning them often enough.Letting brushes sit with a product on them for too long can permanently damage the bristles. It’s advisable to wash them once a month with dish detergent, which breaks down the oils and pigments that build up in the hairs. How you dry your brushes is critical too. After a rinse, lay them flat on a paper towel. “If you put them upright in a cup, water can seep into the base and rot the brush.”
Also, try not to blow-dry your makeup brush. If you’re really desperate to use them asap, then maybe you should try washing the brushes the night before to avoid ruining the bristles.
Thanks for reading.