Generate Press style sheet error

Resource interpreted as Stylesheet but transferred with MIME type text/html: “https://secureservercdn.net/104.238.71.109/pxl.ed7.myftpupload.com/wp-content/plugins/formidable/css/formidableforms.css?ver=392142&time=1615397304”.

I have 12 errors returning this message. Can you tell me how to fix it?

I am also not able to get the page for mobile above 45% quality range. I am using AMP to make the page mobile responsive. Without amp the page speed decreases to 25.

The page I need help with: [log in to see the link]