Your PP rank will fluctuate naturally regardless of if you play or not, especially in the range you're at. Unless you get a higher score with a worse accuracy, this will not happen and what you're seeing is merely your rank jumping up and down in comparison to other players.
PP can punish bad scores, at least I do believe it does in the case of getting a worse accuracy > scoring higher > not moving up significantly much on the leaderboard, but this is nothing you should worry about as such cases will if at all exist, be very rare. Get a higher rank and it will jump around less, as simple as that. Or rather, don't care about your rank at all and focus on improving, having fun, or doing both.
