OK, I just tested it as soon as I hit home. You are the man!
Yes, it was the "tap tempo" feature. I read about it long ago in the manual, but never understood what it was doing... I thought it was sending a midi clock or similar.
(I was thinking that the issue might be related to the "toggle" feature, as it was only happening each other hit of the button, but I was wrong)
Once disabled, the ghost CC is gone. THANKS!