After the last update of
EP-1
1.0.5 → 1.0.8
ARP-2600
1.0.6 → 1.0.9
VOX Super Continental
1.0.5 → 1.0.8
the on/off parameter control no longer works properly with these plugins.
If you assign the FX1 enable parameter to a button, for example, you can switch the effect on or off once. After that it no longer works.
With the previous versions it still worked correctly.
I have reported it to Korg. Maybe someone else can do it so that they understand the priority.