Can't grow radishes

This is my 4th time trying to grow radishes and every single time they come out small and very bitter. I don't know what I'm doing wrong. Grown in raised beds, I made sure soil is loose. Watered daily. Soil is mostly compost, garden soil mixed with a bit of sand and fertilizer. What could be the problem here? Appreciate any feedback.

I'm also growing carrots in the same bed. First time growing them and now I'm worried they will have the same fate.