Robots type enemies are uinlootable, that may be because of the hitbox is missing, but this perk is 3 points of unrewarding , should be hotfixed.
The mechs in the end of the maelstrom fight were lootable for me.. but I don't have the perks so maybe they got it backwards? Both were carrying purple items although I can't remember what they were.
Some human enemies bug out too, seems to happen when dropping near static objects. I always try to get people to die unobstructed and out in the open. It's an easy work around. Robots have a few more problems with this, but it's not a big deal. They only seem to drop crafting materials, and you get plenty of those from dismantling equipment. Their weapons should be easily lootable as long as you make sure they aren't dying in an odd way, which isn't too hard to achieve.
I think those are two different things, for humans, i can reload as well. But for the extra drop of mods from drone and robots after accuiring the skill, nothing seems to help...For human enemies you can save/load and usually that fixes it. I have run into instances where guns they drop still get stuck in the environment, the body though should drop near you where you can now loot it. Haven't tested it on mechs or robots yet but I assume its a physics issue and should work the same? Will update after I test it.
will try this, thanks @Vronos..When I loot them all at once or start with the regular ingredients I also am able to loot everything. ...