Resolve 15.1 Not playing reverse audio correctly

I have a project that was cut in 14, and wanted to make a few tweaks to the audio before releasing the campaign today. Since the main edit, I've upgraded to 15.1.1.005. A number of issues have cropped up - some OFX filters have disappeared and they periodically reappear, seemingly at random. At this point, all of the OFX filters appear to be back (for now).

The big problem is an audio track is played forward then backward back to back. The backward part no longer has a waveform and it turns out it's no longer at the same part of the audio clip - I have to go searching around to find it; since the waveform doesn't appear backwards in the timeline, it's become a "hunt for it and best guess" type of scenario. Hopefully this gets fixed soon...

Was this working in R14? Because I just tried it in 12.5.6 on an entire source file and reversing the clip completely muted the audio, so I guess back then there was no compatibility to reverse audio.

In R15 I get audio but like you say it's not from the correct part of the source file, and I tried reversing the entire source, saving it out, bringing it in and reversing again, but like with R12.5.6 it was completely mute!

If you instead use the 'Retime Controls'/'Rewind' feature (which acts like a 'boomerang' effect like you describe) you at least get proper reverse audio... the problem is that when it plays forwards again, it doesn't repeat the original audio, it instead plays whatever audio would be there had you not used the Rewind feature

And waveforms are not properly updated to reflect the reversal either.