This is not an error with the bot, the bot is working perfectly fine.
Recently there has been an update to Pokemon Go where the Pokestop will not turn purple or give any exp UNLESS you are able to loot items from it. In other words your bag cannot be full. If your bag is full it will remain blue and as a result the bot sees it as a stop it hasn't looted yet (which it is) and tries to loot it again. PokeFarmer is not at fault here, it's just being tricked into spinning the same Pokestop over and over because the game itself doesn't grant exp for not looting items anymore.