[HELP] i9505 No Audio During Call Only topic

Hello.
First of all I'm sorry if this has been posted somewhere else. I searched and there's nobody that got the same problem as mine.

My problem is a little bit different than most of other users here. Instead of not having any sound, I only don't have any sound when making calls. Even the ringing sound when we supposed to hear after we call someone is not there. Other audio works perfectly, not to mention videos, voip, etc.
and also somehow using bluetooth device for calling works flawlessly

Here's a little info about my phone: (obtained from Samsung Phone Info App)
- i9505 LTE (international)
- Using GPE rom 5.0.1 (clean flash from Slimkat)
- bootloader: I9505XXUFNBE
- baseband: I9505XXUFNBE
- pda: I9505GUEUDNL3
- csc: I9505GXARDNL3

I pretty much tried almost everything I know from the forum (updating baseband, wifi-fix, etc)
I can say that the only think I haven't done is clean flash using odin back to stock firmware, which I'm trying not to do because my internet access right now is pretty much impossible to download file as big as 1GB++

I do really hope you guys can help me.
Thanks.