VL.Audio bug in ToMono?

Dear devs,
I came across this issue in the “FFT Waterfall” example:

The ToMono Node worked yesterday when I ran through the examples, but somehow doesn’t work anymore. Sorry for this confusing description, I would like to provide further information if you give me a direction.

all the best,

is this something you can reproduce when starting vvvv from scratch and then only opening the waterfall example? or does it involve some more steps to reproduce? if so, which?