Bug: Fighters disobaying orders

So, I made some suicide bombers to run a huge bombardment of missiles on frigates. I want them to ignore fighters so they unload their whole payload on the larger ships, so I delete the Engage Fighters command.
However in battle they still fire shots at passing Fighters as they close in on their chosen targets, wasting ammunition.

This is fixed in the next patch, it a quirk of the way the orders currently work.