I tried another one and got similar results, hacked together a multichannel wav with a sine wave at a different frequency for each channel and ran that through jriver then analysed it, result is a mono wav with a missing channel 4, i.e. no LFE channel in the output. I'm quite sure this used to work so will report over at jriver forum to see what is going on.
edit: see https://yabb.jriver....c,111023.0.html appears to be some random defect in this particular installation of jriver :|
edit2: turns it out it is a bug in jriver - https://yabb.jriver.....html#msg767472