Home Cinema - Potplayer - 5.1 Sound Issues

For some time now I am trying to find a solution with some issues I have with my media (PotPlayer) I am using.
I have the SONY VA777ES amplifier.
I cannot 5.1 sound from with audio codecs that are EAC3 & DTS Plus (these are usually codecs from Amazon & Netflix. Pseudo Surround multi).
Also, I don't have a multichannel sound from AAC. (Secondary issue)
I am using the LAV decoder which considers one of the best in the market.

Can someone give me a knowledgeable answer about what is going wrong?
And if someone can direct to where I might find the solution? I have searched for quite some time all the major web sites and no-one explains why.
Thank you all in advance for your time in reading my post.

D>K
PS Please don't give me solutions that are to change the player because that is not the issue