Would need more details to tell if there's actually an issue here, but it's not likely since there's nothing particularly special about the drones in this regard, more likely a misunderstanding of the situation. Curious if you did manage to find something, though.
Need a save file from before it happened (Cogmind keeps earlier save states as backups from before your current turn, in /user/) or a screenshot with the message log and aftermath, and seed (from the run.log file, for example) if there's no save to look at the location in question for ideas.
(I did test situations akin to what you describe but don't see anything out of the ordinary.)