DD of scavenging seems bugged

Detonate Dead of Scavenging doesn't seem to explode some corpses
which detonate just fine with ordinary detonate dead.

Am I missing something here? Are there for example corpses with 0
life that can't be exploded by the scavenging variant, or what? :)

It is not bugged as far as I can tell. I was thinking the same thing when I built my DD build for this season. One of the key items was the Vaal DD of Scavenging. I could not kill things using my skills. In the description for the item it reads:

Targets a corpse, causing it to explode, dealing fire damage. The explosion is not affected by modifiers to spell damage and cannot be reflected. Cannot target corpses that have been created by skills.

Thus you need to kill enemies by other means in order to use DDS on the bodies. Even with the regular DD skill, not all bodies, from what I have notice, explode. My guess is that still applies to DD Scavenging in that not all bodies explode?