Dayjs class undefined at runtime

[ray-overjet]

Describe the bug
Importing the Dayjs class results in undefined at runtime. Command clicking into the Dayjs symbol brings me to the correct definition in index.d.ts as expected. This happens when using require and ESM.

import dayjs from "dayjs";
// OR
const dayjs = require("dayjs");

console.log("dayjs.Dayjs:", dayjs.DayJs);
console.log("dayjs:", dayjs);

Output:

dayjs.Dayjs: undefined

dayjs: [Function: O] {
  extend: [Function (anonymous)],
  locale: [Function: t],
  isDayjs: [Function: S],
  unix: [Function (anonymous)],
  en: {
    name: 'en',
    weekdays: [
      'Sunday',
      'Monday',
      'Tuesday',
      'Wednesday',
      'Thursday',
      'Friday',
      'Saturday'
    ],
    months: [
      'January',   'February',
      'March',     'April',
      'May',       'June',
      'July',      'August',
      'September', 'October',
      'November',  'December'
    ],
    ordinal: [Function: ordinal]
  },
  Ls: {
    en: {
      name: 'en',
      weekdays: [Array],
      months: [Array],
      ordinal: [Function: ordinal]
    }
  },
  p: {}
}

Command clicking Dayjs in vscode brings us to the correct index.d.ts definition:

Expected behavior
The Dayjs class should

Information

• Day.js Version 1.11.13
• OS: macOS
• Browser: Node.js v22
• Time zone: GMT-07:00 DST (Pacific Daylight Time)