MiniPEG-style envelope in Gen~ not returning to 0 in one-shot mode (issue with go.uni.gauss?)

I tried to build this envelope generator as a replica of the Eurorack MiniPEG module. The signal is driven by a main phasor that controls the envelope length, and there’s the option to use the envelope either in loop mode or as a single shot.

The envelope shape is based on window envelope functions from the GO book by Wakefield and Taylor

, which approximate quite closely the shapes available in the original project. The issue is that for some parameter values (i.e., certain shapes), in one-shot mode, if I don’t receive any trigger I don’t get 0 at the output.

By design this happens for shape parameter ranges around [0, ~0.15] and [~0.5, ~0.8].

I suspect the problem is caused by the shaping function go.uni.gauss. I tried other functions, but none of them work as well as this one in terms of matching the desired shapes. Does anyone have an idea how this could be fixed?