Custom JS code doesn’t work

Hello,

I created a simple calculator and it works well. When I insert the code into Elementor widget of HTML, the button doesn’t work at all.
I place the HTML and JS inside the HTML widget also by using <script> tag, and the CSS in the custom CSS area.

This is the entire project in Codepen: https://codepen.io/SoPH89/pen/yLRGjqB
You can see that the button is doing the calculation but on Elementor it just keeps on returning 1, and that’s also what I get in the console.log.

Is there a possibiltiy that Elementor code is somehow blocking the JS code?
Thank you very much.

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