Vertical scrollbar breaks after pasting text

[WizX20]

Version

• WinMerge 2.16.6.0 x86
• Windows 10 Pro

Steps to reproduce

1. Open WinMerge
2. Create a new file (CTRL+N)
3. Paste text in the left pane
4. Scrolling vertically does not work properly; in the example screenshot below the pasted text has a total of 315 lines but the scrollbar to scroll up or down is missing/not working as expected.

[mdell-seradex]

I have seen this for quite some time, and while it is a little annoying at times since I typically paste approximately the same number of lines in both panes, which eliminates the issue, I have ignored it.