Hi @zipkinci,
Thank you for the information.
You can fix this issue using this CSS code:
@media screen and (max-width:600px) {
.mce-container-body .mce-container.mce-form.mce-abs-layout-item{width: 94% !important;}
body.wpforo .mce-container.mce-panel .mce-container.mce-panel.mce-foot, body.wpforo .mce-container.mce-panel .mce-container-body.mce-abs-layout {width: 94% !important;}
}
Put it in Forums > Settings > Styles > Custom CSS Code textarea, save, delete all caches, use mobile browser incognito/private session to check, this will avoid mobile browser hard caches.