Hi @vasili111
Welcome to the Dash community.
Dash apps are built in a way that allows hundreds of people to use them at the same time. That is why data should not change in the app globally if the user updates something. For example, if I change your datatable global variables, all the other users would see my change with the new data. And if I put in the wrong data which broke the graphs on the apps, all other users would see a broken app.
That is why, by default, you shouldn’t allow users to change global data. Here you can read more about it.
If you really want changes to be saved for each user, you should probably connect your app to a database like postgresql where changed data can be saved without changing the variables inside the app. Or if you insist, you can read more about going global here.