Why PPS file wont advance slides automatically in Impress?

I have a powerpoint show that works fine in powerpoint when running slideshow. the slides advance automatically. However when I send it to people with Impress it will only advance on mouse clicks or enter button presses etc.

Is there a global auto slide advance setting for slideshows hidden in Impress somewhere that could help? Or is this something else?

Many thanks

Is that the slideshow you attached to your tdf#128926 (that you created in your other question) - which doesn’t automatically advance in PowerPoint 2016 for me; or is that some other slideshow - that again would show some bug in LO?