In Firefox the slide progression advances by collapsing the frame before displaying or while transitioning to the next slide. This is not only unattractive but also disrupts the user interaction with the page.
See the left hand column, desktop environment, https://news.ccansw.org.au
These screen dumps demonstrate what we're seeing in Firefox 84.0.2 (64-bit) on Linux:
Our tests confirm the problem is not present in Opera or Chrome.
Can you advise how we might overcome the issue?