I'm still not seeing what you're seeing, and I am not completly certain I understand the problem, but I don't dispute the fact something is not working properly with your iPhone. I'd contact Apple about it using the Feedback - Safari - Apple link Allan Jones provided, or contacting Apple directly using the Support link below.
This is how your screenshot appears on my iPhone; the most obvious difference is the lack of the URL (discussions.apple.com) in your scerenshot.

Everything scrolls correctly, text fields, copy / paste, etc all working as they always have. The Glass effect can take some getting used to but that doesn't explain everything.
This particular site (Apple Support Communities) had some visibility rendering difficulties a few days ago on iOS devices, but that appears to have been fixed on the Apple Support Communities end. All similar sites worked fine.
So... contact Apple.