No audio indication for call waiting

REPRODUCIBILITY (% or how often): 100%
BUILD ID = OS VERSION (Settings > About product): 3.4.0.24
HARDWARE (Jolla1, Tablet, XA2,…): Xperia 10
UI LANGUAGE: Slovenian
REGRESSION: (compared to previous public release: Yes, No, ?): been happening since I switched to Xperia 10 in February

DESCRIPTION:

On Xperia X, I’d hear a tone if I had another call come in while I was already on a call, but since I switched to Xperia 10, there’s no audio to alert me about a waiting call.

PRECONDITIONS:

/

STEPS TO REPRODUCE:

  1. Be on a call
  2. Have another number call you

EXPECTED RESULT:

Hear a tone alert for incoming call

ACTUAL RESULT:

No audio alert