Default [Q] Muffled sound in call when on speaker

Recently got myself a LG G2. Only issue I'm having is the person I'm talking to during a call can barely hear me (muffled and quiet). It works fine in a normal call regardless of the voice enhancement/cancellation being on or off. Problem only occurs with speaker. Sound is the same whether I'm talking in to bottom microphone or the top microphone. Phone is not rooted

I updated the phone a couple weeks ago. I remember using speaker in call with out an issue when I first got the phone. I can't remember if I updated to Kitkat and had it working. Or if updating to Kitkat has caused the problem

Also, NO sound appears to be sent when using Viber with speaker 'on'. However, speaker 'off' works fine

Android 4.4.2
Kernel 3.4.0
Software Version D80220a-AME-XX

Thanks in advance
Mark