Hi,
when I try to load Renoise 3.0.1 songs produced entirely with the multitimbral version of the farbrausch v2 synth (one instance and several aliases of that instance) into Renoise 3.1, Note-Off for all aliases only works on one Renoise note column.
You can have a look at the attached minimal non-working example XRNS. I added an instance of the VSTi (non-single) and two aliases. The presets are changed via MIDI program change commands. The free VSTi version of the synth can be downloaded here.
The behaviour can be reproduced as follows: Load the example XRNS and trigger/release a note on the first column for one of the aliases: the note stops/fades as expected. Now Tab-jump to one of the columns except the first one and again trigger/release a note: it continues playing. When you now click the Stop button, the current column becomes the new “first column” which allows Note-Off while all others ignore it. This can be repeated indefinitely. 