Cant move tracks?

Hello to all,

For some reason everything i recorded in my track I cant move left or right all as sudden. Do you know what is going on?

When I close the Cubase and reopen the project, I am able to move the content of a track, but when I press alt on my keyboard or ctrl it freezes in place again and cant move it anymore.

Please let me know if you have any ideas that might help,