Need Help in JavaScript

Hey everyone, I built a Tetrino game with HTML, CSS, and JavaScript, but I’m facing three issues:

1. Tetrino Sinking – Pieces drop one extra step after touching another.

2. Game-breaking Error – Second Tetrino at the base causes: Uncaught TypeError: Cannot read properties of undefined (reading 'classList').

3. Scoring Bug – Score increases on contact instead of after a full row is completed.

Any help debugging would be greatly appreciated! Project link: [https://github.com/getnetassefa1/tetrino-project]

Thanks!