UPF Textbox ScrollToEnd scrolls to one line above end.

I have a read only textbox in UPF that is created via

<TextBox Name="chatTextBox" Grid.Row="0" Grid.Column="0" VerticalScrollBarVisibility="Visible" IsReadOnly="True"></TextBox>

I add to it using the code

private void addChatText(string text)
            {
                bool scrolledToBottom = chatTextBox?.VerticalOffset > chatTextBox?.ExtentHeight - chatTextBox?.ViewportHeight - 50;
                chatTextBox?.AppendText(text + "\n");
                if (scrolledToBottom)
                {
                    chatTextBox?.ScrollToEnd();
                }
            }

The detection of the bottom works well enough, but when scroll to end is fired it ends up scrolling to one line above the end. In my code you can see that I end with a new line, this is what I am currently doing as a workaround (where otherwise i would add new lines at the beginning of all but the first line)

For stuff I have tried making sure all of this runs in the UV event loop (doesn't seem to affect things either way/doesn't fix the bug), I have also tried sending only the scroll to the event loop only as a method of delaying the call, but this still gives the same effect.

For my system info, Manjaro Linux running KDE Dotnet Core 3.1

An image of where scroll to end will scroll to.

An image of the actual end of the line, with no newline at the end this would be cutting a line of text.

UltravioletFramework / ultraviolet

UPF Textbox ScrollToEnd scrolls to one line above end. #129