Hello, @oscardc,
To be very clear, we have not faced such issue before, and no any other customer notified this issue to us, you are the first one.
And I am sure, it has nothing to do with our theme, as you also claimed that it happens sometimes and not every time, so if it is because of our theme then it should not have to show even a single time as well. Right?
Finally, I have provided you with all the possible screenshots and video proof as well, that when I debugged which I explained in my previous reply it worked.
Now the final solution is, I suggest you to try on any other computer on a very fresh browser where you did not access your site before and check the behavior.
Regards 8Themes Team.