We've received the sample project.
Both on desktop (Windows with Chrome browser) and on mobile (Android & Chrome browser) I can drag the screen a little bit to the right and then to the left.
However this seems to come from the applied Bootstrap in your item template:
When you uncheck/delete margin-right, the horizontal slider disappears. A quick search about Bootstrap's row class shows the following, so it's not an issue with the TWebContinuousScroll component.