Putty Telnetsession does not refresh list when scrolling.

[Oscar de Lathouder]

There's a post on:
https://unix.stackexchange.com/questions/497449/putty-telnetsession-does-not-update-whole-popup-window-scroll-list

I have the following issue: I'm using Putty to operate an application on a Unix system. After some tweaking, I get the response as it should, colors, borders of pop-up screens.
Settings > Anserback to ^E: terminalname,u
Settings > Window > Translation > Remote character set: "Use font encoding"


One thing does not work:
Scrolling a selection-list in a "popup window".

When I scroll down the list, I see the "active selection" move down the list. perfect. But when I reach the end of the screen, the whole "list" should "scroll up". Instead of refreshing the content of this whole window, putty only updates the line at receives the selection-bar.

See screenshot: https://i.stack.imgur.com/5DY9W.png

Did I miss something in the Putty-settings that might influence this?
It works fine with the commercial terminal Reflection from https://www.microfocus.com