Only the C3 sound stops coming out

I am using Cinematic Studio CSS with Cubase 12.0.70. For some reason, when I use the expression map, only the C3 sound stops coming out (it stops accepting the C3 MIDI signal). Other than that, there is no problem at all. Does this happen to you guys?

Hi,

Isn’t the C3 assigned to any Expression Map by any chance? Could you attach a screenshot, please?

Thank you very much.
You were right.
I found C3 in Expression Map.