I'm on version 7.0.4 (build 55). And, I don't think the description gives the bug enough details. I did find a workaround, but it's not nice.
Bug Details: TLDR, when making changes in prefix-lists the software does not clear out the old list and therefore, can't make any changes.
So the bug from above can be re-created by creating a prefix-list, adding it to something (route-map) so it's in use and deploying it. When you go back to make changes and deploy again, those changes on the same seq lines will not be changed (FMC does, but not on the FW). I was able to make it more cursed by making the changes (deleting the old seq number) and I hoped that I could just change the seq number. However, now both seq line numbers are there, even the deleted one. It shows that FMC can't delete the prefix-list when making changes (I'm assuming because it's in use).
Workaround: You are going to have to delete the prefix-list (and anything depending on them), then deploy. Then re-create the prefix-list (this time correct mistakes), then re-deploy. Any additional changes will have to start at the beginning of this workaround.
