EDIT:
Using Version: 4.2.3.3 on windows XP and Win 8.1
It seems that there is an error (tried with two computers / installations of Impress), if you want to animate one long sentence to “scroll through”, which contains more than 60 characters
The behavior of the text animation “scroll through” is deferent if you includes “carriage returns” then the entire text block moves (in stead of scrolling in the text in one row)
Please watch this video which will illustrate the problem
It seems you found a bug, either in a certain version or for a certain OS.
I made a test with LibO 4.2.4.2 on XP. In my case the entire text block moves. The text block can even include carriage returns or bullets.
The little move helped a lot to understand and simulate the situation!!!
Which OS did you use?
Please report a bug.
Edit1
In your video you show a text block with 3 lines.
I used about 5-6 lines with carriage return.
I right clicked in row 3 and selected the Text menu.
Unfortunately I don’ t know how to make such a smart video.
Edit2
Thanks for your comment. Thus you identified the bug in more details. May I ask you to please report and post the bug number here to enable others to add information. The more information the QA team has, the easier it is to fix the bug.
May I ask why you use this kind of text animation?
Now I completely understand you
Yes if you are using “carriage return” - the entire text is moving - if you do not using “carriage return” and just write one long sentence, which spans over 2 rows - then after hitting the F5 key the text is moving in one row - but if the long sentence spans over 3 or more rows - then the bug is showing
I have edit the original problem description to clarify the issue, hopefully 
Please add this ‘answer’ as a comment to your question - answers should answer the main question. Thanks!