Portal Scrolling on parent record change

On my layout I have a portal that sometimes has more records than will conveniently fit on the screen. Each time the parent record is browsed, I'd like the portal to reset and display the first row first. For example, when changing from Parent record 1 with 10 portal rows to Parent record 2 with 25 rows and scrolling to edit row 20, then changing back and forth between parent records, Parent record 2 stays where it was when I was editing it. I'd like it to "refresh" and start at the top.

Does this make sense? Is there an easy script step to achieve this?

Nevermind - found Scroll Window [Home] as a layout script trigger works.

There's no need for a trigger:
In the settings for every portal there is a checkbox to reset the portal's scrolling when changing the record. Unfortunately I develop in German, so a screenshot might not be helpful. But I'm confident you will find it.

Yes, I tried that, but it didn't work. Odd.