Controlling LEDs on BLE Nano V2


I have purchased several BLE Nano V2s. I’m trying to use my arduino code to turn on and off LEDs that I have connected to the D0 and D1 pins, but it seems like trying to address them is causing the BLE functionality to crash. If I try to turn on and off D1, I can only read about ~15 times from the Nano over BLE before it freezes. If I try to turn on and off D0, I can’t connect to the BLE Nano at all, although it does advertise.

Any help for how I can control these LEDs would be much appreciated, as they’re soldered onto a PCB that I would really like to not have to reroute. Alternatively, if I have to reroute, which pins can I reroute to?

If it helps, I’m trying to turn them on and off by simply adding to the HRM example code in the periodic callback function