I get the same issue with GSnap, irrespective of attack time. Whatever the sample rate, 10 milliseconds of silent audio are inserted at the start of the processed selection, and 10 milliseconds of the selection are removed at the end.
I have not tried GSnap in other hosts but I think the issue is probably Audacity’s lack of buffer delay compensation: https://forum.audacityteam.org/t/vst-effects-8192-samples-delay/26933/1 .
You could try Effect > Truncate Silence after GSnap.
Gale