There is a annoying web design flaw in the mobile phone (portrait mode) forum design that is causing horizontal scroll in the mobile (phone) browser. The effect is that when you scroll up or down the page is moving to the right or left. Most users use portrait mode on their phone so that has to be taken in account when designing a website.
The cause is that the content is to wide for the view port, because of the “profile image”, “Views” and the “Time stamp” next to the post.
The solution is simple and can be done with a media query and some lines of CSS that is placing the above named items at the bottom or on top of the post instead of next to it at a certain device width (around 380px/500px)!
When you show this to your web designer he or she can fix it in a couple of minutes.
And open the page in Chrome Windows on the desktop:
More tools > Developer tools > click the responsive icon (2 mobile devices in portrait mode) > Choose in the middle of the top screen your mobile device (iPhone 6/7/8 for example) and notice there is no horizontal scroll on neither the main forum page as in the individual posters page.
Now try the same with the Topaz Forum page and you notice there is something wrong, because there you see horizontal scroll.
This implicates something in the original code from the discourse forum framework is changed for the worse.