So lately i have noticed my car is not as loud as it used to be...

I was playing one of my favorite songs- 'Sidity- Roscoe Dash' and at the begning of the song there is a part where the music goes from left speaker to right speaker and back to right. Problem is i can only hear the left part.

To make this even more complicated all 3 speaker on the right + the tweater work fine during the music

I checked the balance settings and its a 0 so it's not that
Is something wrong with my amp by any chance? I have HK on my car!
Any way to reset the CD player?

Asking help from all the Audio pros here

Thanks