Users are experiencing issues responding to posts on their cellphones, specifically with the "Reply" option and cursor behavior. The problem seems to occur on a Samsung S11, where the website functions correctly on a computer but not on mobile. Users report difficulties such as being forced into the original post's box and cursor jumping around when trying to respond. Suggestions for troubleshooting include checking the phone model, browser, and version, as well as testing inputs on other websites. Overall, the discussion seeks solutions for mobile responsiveness issues on the forum.