FreeRTOS LoRAWAN AT Commands wont work

I’m having an issue from the tutorial: LoRa-E5 DevBoard under FreeRTOS LoRaWAN AT. After successfully completing the tutorial, I’m unable to execute any other commands than AT? and AT+JOIN=1. If I try to get the version by using AT+VER I just get the error message: AT_ERROR even though the syntax should be correct. Does anybody know what is wrong or is experiencing something similiar?