Thank you for your post.
Our Development and Testing departments are aware of this issue of script steps jumping to other lines. I have attached your post to the original report. When more information becomes available, I will let you know.
For More Information see: FMPA14 Script step line jumping
This is one of many acknowledged bugs that can be found in the Known Bug List thread here in the Report an Issue section of the forum.
It can also be downloaded as a database file from: https://www.dropbox.com/s/jt09b82i0xijbu3/FMP%20Bugs.zip