otSetStateChangedCallback gives OT_ERROR_NO_BUFS error

[sailsimple]

When I call the function after connecting to the thread network I get a NoBufs error:

openthread_context *threadContext = openthread_get_default_context();
error = otSetStateChangedCallback(gInstance, HandleThreadStateChanged, threadContext);
if (error != OT_ERROR_NONE) {
LOG_ERR("Failed to set state changed callback: %s", otThreadErrorToString(error));
return;
}

My handler:

void HandleThreadStateChanged(otChangedFlags flags, void *context)
{
    if (flags & OT_CHANGED_THREAD_ROLE)
    {
        otDeviceRole role = otThreadGetDeviceRole(static_cast<otInstance *>(context));
        LOG_INF("Thread role changed: %d", role);

        switch (role)
        {
        case OT_DEVICE_ROLE_DISABLED:
            LOG_INF("Thread network is disabled");
            break;
        case OT_DEVICE_ROLE_DETACHED:
            LOG_INF("Thread network is detached");
            break;
        case OT_DEVICE_ROLE_CHILD:
            LOG_INF("Thread network is connected as a child");
            break;
        case OT_DEVICE_ROLE_ROUTER:
            LOG_INF("Thread network is connected as a router");
            break;
        case OT_DEVICE_ROLE_LEADER:
            LOG_INF("Thread network is connected as a leader");
            break;
        default:
            LOG_INF("Unknown Thread role");
            break;
        }
    }
}

I'm using an nrf52840-DK and am guessing that it needs more resources, does anyone know which configs to update?