Serial Monitor not functioning

I am using an atcommand in the adafruit bluefruitle nrf51 library.
The serial monitor keeps filling with these characters, and I am not sure what to do.

Are you using the same Baud rate in platformio.ini as in Serial.begin(9600)

Yes, I have monitor_speed = 9600 in my .ini, and Serial.begin(9600); in my .ino

Does it ever advance? With the factory reset option enabled it will reset the firmware to the factory one, during the flashing process I expect the chip to momentarily put out garbage on the UART line – but it should finish at one point.

If it never goes past that you should try and manually do a factor reset / DFU in accordance to BLE FAQ | Adafruit Feather 32u4 Bluefruit LE | Adafruit Learning System, section “My Bluefruit LE device is stuck in DFU mode … what can I do?”.

Then you also don’t need to activate the FACTORY_RESET macro.

It appears to be running infinitely, I ran it for 1 hour and had no stopping point, I already reset the device and reinstalled the firmware.

If the device is reset, does the firmware work with FACTORY_RESET macro set to 1?