Midi Notes already recorded drop when midi merge recording

[EdwardG]

Well that is weird cant remember it happening before...

I have a client recording drums in a keyboard he plays kick and snare and then with recording with midi merge active he records hats and cymbals but what happens is that when a note is played at the same time a midi note from those kicks and snares is playing those snares anb kicks stop sounding, and its difficult to record this way, happen to someone? Any ideas? is this normal?

AS far as i remember it never happened before
have no time right now to mess up with trashing preferences etc
to many things to redo if I do and cant right now...