Malformed ULID string generated

[larrystone]

Hello,

We recently stumbled upon a couple of invalid ULID IDs on our system. This happened between 2025-07-23 and 2025-07-25.

Examples: KQHLZWJQ8MJJDH67LRIMHIHRSL, NPPRAZVV1OIVWL06NJ7W1VJZFB, G551GVXZAM7M95HVQNEZO8YXYS

Here is what our code looks like

import { ulid } from 'ulid';

export const generateId = () => ulid();

ulid version: "^2.3.0"

Code Environment: NodeJs + koaJs

Node version: 22