The "sentient" class amalgam enemies that spawn in the secret rooms on Jupiter missions have several exlusive mods that they are supposed to drop.
These specific mods (Anti-Grav Array, Odomedic, Gale Kick, and Kavat's Grace) appear to be bugged once again, the enemies appear to be bugged where they don't actually drop the mods. The enemies appear to drop a mod when you kill them, but upon picking up the mod you don't actually get a pickup notification, and no mod is listed in your mission rewards.
This bug was listed as fixed in Hotfix 25.0.4 "Fixed Kavat's Grace, Gale Kick, Anti-Grav Array, and Odomedic not actually dropping from Amalgam enemies.", but it appears to have become broken once again in one of the subsequent patches, since this is appears to be the same thing that was occurring prior to that patch when it was fixed.