Weird disappearing delay - filterbank ring mod

    This is weird and I wonder if anyone here can unravel it.
    Go to an init patch.
    Add some delay.
    Go to the Filterbank and add Ring Modulation, Mix 100%, Frequency +0, Stereo Phase -64
    The delay disappears.
    Move frequency to anything but +0 it comes back.
    Move Stereo Phase to anything but -64 and it comes back.


    Anyone know enough about what's going on here under the hood to explain it?
    Thanks

    It could be that in -64 the left and right channels are completely inverted with respect to each other. If the delay effect uses a mono mix as an input in this case it will get silence. That's very easy to check: record the sound with stereo phase at -64 in your DAW, then set the track to a mono mix and play it back. Inverted left and right channels should cancel each other.