No beep tone from Varia

No beep sound can be heard. I made sure i  enable tone via alert setting in garmin 1040  Still can't get a beep sound to notify me when a vehicle is approaching from my Varia 715. I can see from my screen that vehicle is approaching but cant hear the beep. it used to work but all of a sudden it stopped.

i have :

1. Updated software to latest

2. Reset 1040 computer

3. Gone to the varia app to check 

4. sound can be heard from my phone but when i disconnect the varia app , no beep can be heard from the 1040