Cannot save worlds onto internal memory

My phone lacks an external sd card as the card reader stopped working a while back so having one was pointless. Recently, while playing Minecraft PE, I realized that the worlds were not saving to the internal memory like every other game on my phone does. The worlds, settings data, etc, are trying to save to a sd card that does not exist, so why is it that every other game I have save it to the default location in the internal memory and Minecraft PE does not? Bug? Issue?