From my understanding males have scatted spots (freckling) and looks like your dovi is starting to freckle all over the body, so im leaning towards a male. Plus it also has spots on the gill plates which is another male trait. Just looks a bit washed out in colour due to your tank being so bright.
Im in the same position as you and also questioning the sex of my dovii. Ive been growing out a dovii for a month now and its also around the 3 inch mark. I did a vent check and im pretty sure its a male from what ive researched on what to look for when venting, but im no expert and not 100% sure. Apparently at 5 inches its really easy to tell the sex of doviis.