Drum track changes

Hi everyone, I am encountering a strange behavior: I have a midi drum track and a clip on it. I’m editing the piano roll, and when I change something and play it - it doesn’t play what is written, still plays the former version. When I take the clip and put it on another midi track and put it back on the original track again, then it works and the changes are there.

???

anyone knows what’s going on?