Keep Closed Duration value 0 not working on overlay

From the overlay documentation:

‘Setting the Keep Closed Duration value to 0 will prevent the overlay panel to current browser session only. Meaning whilst the site remains open in the browser, the overlay will not re-appear.’

This does not seem to be working for me.

I have set the Keep Closed Duration value to 0, but the overlay keeps opening on every page even after closing the overlay with the X close button that I added to it.

My overlay is a time delay one.

I have NOT checked any of these options
Close on ESC key
Close on click outside
Disable page scroll

Setting the Keep Closed Duration to a number greater than 0, does work correctly

I have added URL details to the private info.