:-)
I use 2 features of the PrimeNG table (<p-table>, Version 8) in combination:
This works quite well as long as the table is indeed scrollable:

But when to many rows are collapsed the table is smaller than the threashold scrollHeight I configured at the p-table. That makes the scrollbar go away so that the table body fills up that space - without the header getting wider too:

What I tried so far
- Force the scrollbar: According to this article giving an html element the css style
overflow-y: scrollenforces the scrollbar to allways be visible. However the scrollable element I deal with here is generated by PrimeNG and so far I couldn't overwrite it's style - Use
position: stickyto make the header follow: I already blowed hours in applying that attribute to the header. It never took effect. Thats why I tried this with thescrollablefunction ofp-tablein the first place.
May the force be with you!