A waterproof shell that “wets out” usually is not broken — it just needs cleaning. Dirt and body oils clog the fabric and defeat the DWR finish.
Wash technical shells with a dedicated tech wash, never standard detergent, which leaves a residue that attracts water. Skip fabric softener entirely.
After washing, a low-heat tumble dry reactivates the factory DWR. When water stops beading even after cleaning, apply a wash-in or spray-on DWR treatment to restore it.