It would be useful to know what concentration of DAPI you used and fore how long in order to troubleshot.
Additionally, there are some very bright spots present, and I'm uncertain whether they are cells or debris. If you have exposure set on automatic this could be causing your microscope to adjust gain or exposure time to this very bright sports leaving your nuclei underexposed. Could also be that you have your contrast set in automatic in the software in which you are seeing/exporting the images and again this bright spots are interfering. If the second is true, then you would only need to adjust your contrast before exporting, overexposing those dots but correctly exposing your cells.
You mentioned that is a confocal image, take into account that confocal microscopes use pinholes to get light from a thin section of your preparation, mainly the part that is on-focus (depending on the pinhole size and the wavelenght used) therefore if you don't have all the cells on the same focal plane, you should consider using a Z-stack. I would also consider not enough permeabilization time or strenght and the concentration and exposure time to DAPI. I hope you already solved the issue by now!