Is it obligatory to repeat the Dhuhr prayer after performing ghusl from janabah if, later, remnants of janabah are discovered on the male organ?

If the emission of semen is confirmed after Dhuhr prayer, the prayer does not need to be repeated, because the hadath (ritual impurity) is attributed to the nearest time. However, ghusl (ritual bath) is required for Asr prayer. But if the semen cannot be considered a new occurrence after Dhuhr prayer, and it formed a barrier preventing water from reaching the skin, then the area must be washed with the intention of removing the hadath, and Dhuhr prayer must be repeated.