Why is Binance mobile app auto-changing limit orders to market price?

When setting a limit order, the mobile app (Android) seems to be automatically changing my buy or sell price to the market price, about once every few seconds (or whenever the market price changes). So that if you want to enter an order at your desired price, you have to hit the buy/sell button instantly after setting your price or Binance will mess up your order.

Is this a common user-side bug? If so, how do you stop it from happening? Or is this some sort of twisted "feature"?