Good catch.

I verified your findings, and perhaps found the reason why.

When toggling through the sub options i noticed:

that pressing the remote LEft button toggles from none - L/R + sub - LFE -none

Heres the bug
go from LFE-> NONE, THEN press the Right arrow button and it jumps to L/R + sub.

IT SHOULD goto LFE before toggling to L/R +sub. Perhaps this issues 'confuses' the unit. Definitely a confirmed bug.

I got my hopes up, and that it would solve the No bass redirection in L/R + sub, But alas, like you said, it did not help.

Also a note I tried from LFE - none ,and it did fix the Fronts double bass issue, But i did Not have any output to the sub. I am running is Stereo Mode, and all speakers set to large. (Digital Signal used)

Perhaps you still got redirection to the sub from a 'small' speakers setting. PERhaps to do with the bug i found that when in stereo (Sub = LFE Only test above in digital) , and the Sides surr set to SMALL that there was bass injected into the system. (even though it should be STEREO/ or BYPASS)