I also just experienced this issue BIG TIME.
To the extent where it basically broke our game.
I'm using 1.12 ofcourse.
Here's the situation.
A large amount of these ships (Assailants and Sentintels) came in via phase gates (Dark Fleet)
The ability is on autocast by default.
It seems a large amount of these ships came in with the ability ON for some reason, which means they didn't move from the start. It is also possible this could have been due to rebel raids (my opponent was TEC)
They WOULD NOT automatically go back to normal mode, even when they were completely alone away from enemy units. So they remained stuck in non-moveable mode the whole time, meaning I couldn't even move them between my planets.
So I figure.. no worries. Sure this is annoying as shit, but I'll just turn off auto-cast and select them all and turn them back to normal.... easy right? NOPE!
I could turn off auto-cast on multiple units of the same type at once, but couldn't set them back to normal by mass. I had to literally do it ONE BY ONE. (ie. If I selected a group of 10 Assailants, toggled the ability back to 'normal missiles' only 1 of the 10 would actually change).
In my opinion this is a bug and needs to be fixed. Either fix the AI so it toggles the ability off/on properly, or make it so autocast is not on by default AND and you turn off the ability for multiple units at once.
This is BROKEN, there is no doubt.