"Volume pedal to wah" problem

In order to use my Kemper for the first time at a live gig, I needed to implement some functionalities I depend upon, like using a volume pedal that changes to wah when it is engaged, and back. Searching the forum and manual i found that Kemper wont implement that function, but have the "volume to wah" option, in which when in a rig there's an active wah module the exp pedal works like a wah and when desactivated, the exp pedal works like a volume (sorry for my bad english please!). I have a Liquid Foot Jr controller. I did the programming. The first "oops": the Kemper expects to see WAH CC (#1) in order this function to work. I assumed that Volume (CC #7) would be the logic choice, but after failing i programmed in the Liquid Foot CC #1 and it finally worked, so no big deal and solved (could it be better named "wah pedal to volume"? ). So I had "Volume pedal to wah" working fine, my exp pedal was a volume, then i activate the wah and it became a wah, de-activate and it came back to be a volume. And then the PROBLEM came: after like 15 minutes and after some rig changes by midi PCs in PERFORMANCE mode, the "come back" to volume after wah disengaging begun to lag, that is the volume pedal function returned after a few seconds at first, then the lag grew up, till at half the gig, it wont return to volume for the rest of the song. And finally, sometimes at slot change the volume worked and sometimes dont (I have other rigs in the same performance which I dont use volume so i didnt programmed it). Could it be a bug? Any sugestions? Help! Regards!