my s8 wont play in 5.1 on bluetooth, but it does when plugged in direct

[Android Central Question]

i like to listen to my music loud when i am in my shop. my S8 while on bluetooth only plays in my front two speakers and through my sub. my center and nmy surround has no music. If i plug my phone into my receiver directly all 5 of my speakers then play. Bluetooth sounds much better than direct plug, and i cant figure out why my S8 wont play in 5.1 while on bluetooth. please help!!