STrawberry flowers problem?

I couldn't find anything with such specific problems as your plant. It could possibly be from two sources, either a fungus or a pest, and without a photo its hard to determine. Personally, I'd pick off those problem flowers and burn them and watch for future flowers that are the same. In the meantime, keep your watering more even as the plants really do suffer from inconsistent watering, even after fruiting. Pull away any mulches for the time being in case its hosting the pest causing the problem. And don't feed with high nitrogen fertilizer as this shoots the plant into quick, rampant green growth that will attract many more bugs. If the plant continues to put out these damaged flowers, pull it out and burn it.