Hi, you have performed a clean installation of the software?
Just tried that. Removed XD and preferences - did not help.
No scroll bars visible in either Safari or Firefox on iMac Mojave. System is up to date.
Could you insert a screen? So we can help you better
Sorry, what do you mean by 'screen'?
I included a link to the prototype in the post.
I'm sorry, I didn't see the link you posted. However, it is very strange that the side scroll bars do not appear. By chance, have you also tried a web artboard?
Just tested this on my home computer with Windows 10 - same issue. No scrollbars, not possible to use arrow keys up/down or Page up/Page down to scroll page. These keys all work on older XD prototypes. My Windows mouse scroll wheel does however make the page scroll.
I see what you mean. However, the scrollbar that you see looks like the scrollbar for the browser and not something that is generated by XD. I could be wrong, however, and would want the other contributors here to weigh in.