A DRIP — dividend reinvestment plan — takes each cash dividend on its payment date and buys more of the same shares with it, usually including a fraction. You were still paid; you just spent it straight away. That's reinvestment. Funds can do it internally instead: with accumulation units, the income stays inside the fund and lifts the unit price, and no cash or new units appear at all.
Each reinvestment is a new purchase at that day's price, so it adds shares and adds to your cost basis — the dividend becomes money you've put in. The app books the dividend itself automatically, but it can't see what your broker did with it: add each reinvestment as a small buy, or bring it in through your broker connection or a CSV import, so the share count and cost basis stay right.
The cash never reaches you. It arrives as shares, and your cost basis grows with it.
Educational content only. It is not personal financial advice.