Text running off the webpage in certain browsers

I have a website that works fine in chrome, edge, safari, but on the mobile version of Firefox, duck duck go, and facebook the text won't resize to fit the screen. I've even noticed xara's sample website does the same thing.

http://previews.xara.hosting/vue/

Other sites do not do this. Does anyone have any idea why and how to fix it?
Is this something inherent in xara?

Please Help!!!

Mylon Avery

HTTP://www.mylonavery.org

I have just used Android DDG on the demo site with no problems.
Your two church sites also behave.

I didn't know FB was a browser too.

Might it be as simply as double-tapping the page or pinching it to fit.

The Vue example was generated by a fairly old Xara HTML Filter so it is not representative. If does have <meta name="viewport" content="width=device-width, initial-scale=1" /> included.

Acorn

Thank you