The following code will trigger the issue:
<ins author="Test user1" command="Insert" timestamp="1488935783059" title="Inserted by Test user1 on 3/7/2017, 5:16:23 PM" class="reU7">
<p cssproperty="verticalAlign" author="Test User2" timestamp="1488945891760" title="Formatted by Test User2 on 3/7/2017, 8:04:51 PM" class="reFormat reU0" command="Remove alignment"><span style="font-size: 12pt;">&nbsp;</span><span style="font-size: 12pt; font-family: 'Times New Roman';">This is some sample text.</span></p>
</ins>
When track changes are enabled and you try to delete from the end of this text, the deleted characters move to the following lines with a strikethrough rather than just deleting.