Unless I'm wrong, player settings are not relevant in this case. We can choose either PCM or bitstream, but as the source music is in PCM, what it's being sent to the AVR is the same, isn't it? In any case, I tried yesterday changing the parameter and got the same behaviour.This is exactly what I tried to explain in an earlier post.
Check the Oppo and try changing the output settings. I think my Oppo 83 will pass 4.0 properly and it is a generation older than your 93
Funnily, the Dolby encoded DVD plays fine in 4.0, I need to understand why