I had the same issue. To get it working again i deactivated the mod, loaded the game, saved it (without the mod) and activated the mod again. After that it worked but all drones were gone obviously.
It was on a heavily modded game but i dont had any issues before.
if you want to check it out here is the save: https://www.dropbox.com/s/el8lm9rcyrk35vl/bobs%20angels%20hell_companion%20drones%20bug.zip?dl=0
Yeah, happens semi-randomly. In my game things broke after one of drones got destroyed. And also they were building when shortcut "build toggle" was off. Weird stuff.
In the end, placing and entering a vehicle fixed the issue.
I have also this issue: one drone of two gets destroyed. I build a second, but it won't do anything anymore, no matter how I equip it.
Tell me, if you need the save.
I have sometimes found that if a drone gets a little lazy that it will change its tune if I put it in time out. (Read: mine the drone to inventory and re-deploy)
