Limit on number of items in KDE Plasma5 (Leap 42.2) panel dropdown lists

Excuse me if I use the wrong vocabulary for KDE Plasma. I have noticed that when I have more than 14 documents open in Okular (yes, I sometimes need them all open at once) only the first 14 are listed in the dropdown (or “dropup”) box from the Plasma task panel. A 15th document will half appear at the bottom of the list and any more documents do not appear at all. Experimenting with other applications (such as Dolphin) shows the same limit. Is there any way to tell Plasma that if I want more than 14 files open, then I really do want more than 14 items in the dropdown list, and it really ought to list all of them for me? Or is this limit hard coded into Plasma?

It’s a bug:

The only workaround I know of is disable grouping. (right-click and choose “Task Manager Settings”).

In Plasma 5.10 beta you can also do this on a per-app basis (right-click on the entry and choose “Ungroup”), but I’m not sure that was possible already in 5.8…

Thanks Wolfi. And a very annoying bug it is too.

So it seems I’ll just have to put up with it until a fixed release of Plasma gets included in the openSUSE updates.