Answer
If the price is going past upper limits, it means all your orders now is buy orders which is waiting to be filled. If price comes back to this range, your buy orders will be filled and the money will be used again to put sell orders at 1 grid lower than its selling price. The bot wont stop until either you stop it manually, or it hits the stoploss/Take profit trigger. Also the price range (upper limit and lower limit) wont go automatically higher. If you want to have a bot that has no upper limit, use infinity grid bot instead of normal grid bot.