Funds - Dividends

Hey guys I did do some DD before writing this post but I can't find enough information to help me understand things better and hence asking here How does Dividend payouts affect navs of various funds - ETF/MF? Im invested in various funds like HDFC defence fund where mazdock recently payed out dividends, INF109KC19W1 - METALIETF where vedanta payed out dividend but NAV is generally unchanged or mostly negative for past 6 months. I had a MF agent set me up some schemes when I was a child where I could see dividend money being used to buy new units (scheme investment records would show +2k inr worth of units purchased which were related to dividends) I understand these plans of dividend reinvestment are now no longer available and most funds will adjust to nav. I also don't expect major bumps since dividend will reduce share prices.