I had same issue with altura Nevis jacket. Tried nikwax spray but no good. With grangers 30 degree proofer, washed first in soap flakes. This is crucial as any other type of detergent stops the proofer from working. Washed in the proofer then tumble dried on low heat which didn't seem to harm the jacket, and did make thr proofer work better. It's only lasted 4-5 months tho so not sure it's a permanant solution