Adjusting voice lines sounds

I tried to search for this problem but didn’t find any discussing it, so here it is.
for some reason the NPC voice lines don’t count as “dialogue sounds” in the settings, but as “sounds FX”. so if I wanted to lower the sounds effects I need to lower the voice lines of the NPC.
personally, I think that does not make sense, and I feel like the NPC voice lines and other voice lines should be in the “dialogue sounds” instead of “sounds FX”.

Strangely, you can lower the dialogue volume and it affects voice lines. I suppose, voice lines are both SFX and dialogue. This way, you cannot increase voice over sound effects. This needs to be patched.