Shadow Wave has a healing priority for its jumps, which looks like this

Wounded real heroes > wounded creeps > full hp real heroes > full hp creeps

But for some reason, it only counts basic creeps here. It completely ignores creeps which have other classifications. Ancient creeps and creep-heroes are not properly prioritised when wounded. Sometimes the spell does heal them, but sometimes it does not.

Example scenario:

You have full hp ally, and a wounded allied Ancient Thunderhide nearby. When you cast Shadow Wave, it targets the hero and the creep at random. It doesn't prioritise the wounded thunderhide over the full hp hero. The same is true when you replace the wounded thunderhide with a wounded spirit bear or other creep-hero. But if you replace it with a regular creep (non-ancient, non-creep-hero), Shadow Wave will prioritise that creep over the hero, if the creep is wounded.

Current behavior: Shadow Wave doesn't consistently prioritise wounded ancients/creep-heroes over full hp heroes/units.

Expected behavior: Wounded ancients/creep-heroes should be treated like other wounded regular creeps.