Firefox not showing website properly

Maybe post a link to the site.

https://www.richersounds.com/tv-projectors/projectors-accessories/projectors/4k-projectors/?sort=PRICE_ASC

https://www.richersounds.com/clearance-bargains/in-store/bristol/

Thanks for the links: Though no idea what properly means to you and I don't use Google or Chrome etc.

Attached an image of what I get on the second link you supplied, maybe an image of what you see as a problem would also have helped understand your query

I mean properly resolve the page, like in your attachment. Instead I just get words of what should be below the heading of the page. I'm attaching of what I get on the same link you tried. Is it something in my Firefox setting or perhaps using dark mode? Clutching at straws here.

I wouldn't have thought it 'dark' mode but could be a theme if you have one.

I notice that you have a text icon I don't have, that could be enabled, not that it may be affecting such.

One option is to use a temporary Profile : See about:profiles and search for more info on that.

Oh and my screenshot is without allowing cookies and cross-site cookies etc. I also see you are using VPN

With cookies enabled I get a different image so maybe somehow you are not allowing some thing via your blocking apps

See screen shot with cookies enabled compared to mt previous image:

This would be some content blocker or "noscript" addon interfering. You can quickly verify by restarting into Troubleshoot Mode (from Help menu) and see if it works there.