neopixels on the nRF52840

I was playing around with the PAN1780 eval kit (it mimics the nRF52840DK closely except for the lack of QSPI) and I seem to have issues with neopixel.

Has anyone been able to get an nRF52840 working with neopixels? Doing something like

require("neopixel").write(D28, [255,0,0]);

seem to lock up the board. The web ide console (connected through ble) stops responding, and a blinky I have running to check if the board was still actually working behind the scenes stops blinking. It doesn't seem to matter whether I have a neopixel connected or not.

Here's what I use for testing this:

let on = 0;

const toggle = () => {
  on = !on;
  digitalWrite(LED1, on);
};

setInterval(toggle, 100);  

setTimeout(()=>{
  require("neopixel").write(D28, [255,0,0]);
}, 1000);

I have an actual nRF52840DK arriving sometime next week so I can see if it's just this particular board that's the problem, but I wanted to see if anyone has had success with neopixels on any kind of board that has the nRF52840 (like the particle boards for example)