Heading Text affected by Test/Plugin

If you this page; https://test.fastpixel.io/cached/websquadron.co.uk/

There is a red/orange block above this text “We’ve got the know-how on high-converting websites for businesses, attracting customers and boosting sales to outpace your competition.” in the Hero Banner.

Compare to the standard page to see the difference: https://websquadron.co.uk

I suspect it’s caused by fpo-lazyloading….

Any ideas?

PS – the CSS used for that Heading is:
selector {
background: #FF0050;
background: linear-gradient(to right, #FF0050 0%, #FF830A 100%);
-webkit-background-clip: text;
-webkit-text-fill-color: transparent;
}