How to fix Sale Badge HTML calculation for multiple variants?

Hey guys, so I wanted to display a sale price which is working if you have 1 variant, but if you have multiple variants with different prices it shows a complete different sale in the Banner.

The HTML Code I am using for calculating the sale price is: {{product.compare_at_price_max | minus: product.price | times:100 | divided_by: product.compare_at_price_max}}

Maybe you can find an issue here

My website is: www.wamula.de

Thank you so much!