No audio playback

So I've been having major audio issues on Adobe Premiere Pro for the past 3 days and it's becoming a huge problem. 
I had to post plain videos with no sound effects due to this;
There is no audio playback on A3 or A4. So basically I can only insert ONE song, and NO sound effects. 
Nothing is muted, both A1 and V1 are selected, And the track IS transferring onto the sequence. 
The only audio that plays and exports with the video is A1 and A2. 
A3 and A4 is nowhere to be heard. 
I tried messing around with monitoring. 
when I enable monitoring audio, i can hear it, but it does not export with the video. 
Any suggestions??
I've been researching this for days and there is no solution. Did I click something on accident? Is premiere pro just glitching? Is it a bug?? 
Please help!