Homogenizing Exalt + Dextral exalt

Had a staff with 2 suffixes:

Cast speed (caster/speed)
+ spell level (no tag)

Homogenizing exalt + dextral exal exalt added:

Gain # mana per enemy killed (mana tag)

I was expecting any of crit chance/dmg since they also have caster tag but got mana.

What does "type" mean at this point?
Does it consider every mod in the staff even i force a suffix to added?
The staff has a mana tag on prefixes so i guess this is why but doesnt feel right.

Yes it was the mana prefix. The homogenizing omen does not mention that it is suffix specific or would change when used with dextral / sinistral omen, so it follows the description and is not a bug.