you mean the win doesn't detect the first time you push the R button, or it only pays a credit or two and you have to push the R button again to keep getting paid more?
it should detect and pay the full amount the first time you push the R button.
in some cases depending on where on the search disc the wins detect and how much a payout is, it's possible the game will pay both an inline win and a section win with one R button press (assuming you have two wins at the same time without needing to move the screen). However, it's more likely you need to press the R button once for each win.
if the game isn't detecting the win, you have to further narrow that down to whether the search wipers are stopping and the sequence/winners unit are doing their thing, or the search wipers aren't stopping.