Phenomenon after version up SyntaxEditor WPF

I did version-up of SysntaxEdiror WPF control from 14.2 to 17.2 or 23.1. For 23.1, I must have made a fix according to the https://www.actiprosoftware.com/docs/controls/wpf/conversion/converting-to-v19-1 page.
But in our application, the following phenomenon that did not occur in 14.2 are occurring.
If you have any hint, could you help me by teaching it?

1. There is a case that the lines are not redraw on scrolling
    before scrolling:

    line 9   aaa
    line 10  bbb
    line 11  1⃣1⃣1⃣　<- highlighted with yellow background
    line 12  ddd

    after scrolling with up arrow key:

    line 8   
    line 9   aaa
    line 10  □□□        <- it seems that yellow background color remains and the text "bbb" is not displayed (just being yellow bar)
    line 11  □□□ 

2. Color indicator for modified lines is not colored
    although SyntaxEditor.AreLineModificationMarksVisible = true.

(Feb. 10 update: The phenomenon don't happen with SyntaxEditor 17.2.)