Novation Impulse Strange MIDI Problems
 

Hello, something rather strange is occurring to my MIDI setup.
I recently bought an Impulse25 and it happens and when using it with pro tools it works in some sessions and in other not. I have checked the peripherals and the MIDI input devices and MIDI studio and everything seems the same in both sessions so I don't know what is happening, please help. I'm in pain.

Thank you so much! (English is not my first language so I hope I made myself understood)

MacBook Pro (late 2011)
High sierra
Pro Tools 12