Firstly on your NPM page: https://www.npmjs.com/package/gsap
The link to the CDN link is wrong: <script src="https://cdnjs.cloudflare.com/ajax/libs/gsap/3.0.1/gsap.min.js"></script>
Secondly tweening between large numbers 0 to 300,000 produces a negative value, in the older versions of GSAP it's working perfectly.
Working version (1.20.4 OLD VERSION):
See the Pen wvvEWoM by JoeCoulam (@JoeCoulam) on CodePen
Latest GSAP