Unable to route Phone Call Audio to Earpiece in Nexus 4

Am using Nexus 4 running on 5.0.1(unrooted). Recently I dropped my phone in water and unable to hear anything in my Media/Phone calls. But later discovered ( googled ) this App and tried to test if there's any problem with my Hardware. I routed Media audio to both earpiece and speaker both are working fine. Also tested MIC functionality by recording a video, it is also working great.

By default SoundAbout says that Wired Headset has been plugged in (Let app decide on Media/Phone call & Wired Headset detection ON). After unchecking 'Wired Headset DEtection' & re-routing the Phone Call Audio to Earpiece, still unable to hear any sound via calls.

The problem is unable to hear any sound on calls through Headset as well as bluetooth,but able to hear media audio on headset as well as bluetooth. So even with soundabout am unable to use my Nexus 4 to make calls through any option..

Do I need to root my nexus 4 for this Phone Call functionality to work or any other advice that could help me here???

It could be a more serious problem, but after switching Wired Headset detection OFF, restart the phone.

Also I created a new Beta version.
https://soundabout.forumotion.com/f8-download-beta-versions

I tried all beta versions, nothing seems to help me here. Did the following,

1. Clear cache, Clear Data & Uninstall current version
2. Reboot
3. Install next beta version (2.6.1.1.2, 2.6.1.1.3, 2.6.1.1.4, 2.6.1.1.5 & 2.6.2.1)
4. By default Status is 'Wired Headset with mic for media' ( Phone Call/Media in 'let app decide' & Wired headset detection 'checked' - both are default values on fresh install)
5. Now uncheck  all options under 'Connectable devices'
6. Restart
7. Now 'Phone speaker' in use for media ( Phone Call/ Media still in 'Let app decide' )

Tried to make a call on lollipop dialer, no sound on both ends (Earpiece & Mic are blank).  

8. Change option of Phone call to 'earpiece / speaker' - No change in above behavior
9. Restart and try again, still no change.

One more info, on clicking 'RED' button to end call.. Usual call ending sound is clearly routed to speaker.

Please clarify if am missing something, if not why there's a problem with 'Phone call' alone. After app installation Media audio is perfectly routed to 'Speaker'.

Help me here, Nexus 4 sits ideal in my desk for around 5 months due to this issue.

The phone may have a more serious problem, so that SoundAbout can't alleviate the issue.

I just published a new version to Google Play.

You can get it early, while it is being processed by Google here:
https://soundabout.forumotion.com/f8-download-beta-versions