Once the computer is turned off and then on again, the historical data you have made available no longer have the historical series imported by me on the quote manager.
When you close MultiCharts and the MultiCharts applications (after importing the data), does a window appear indicating that data is being saved?
If it does not appear, try checking in the Windows Task Manager => Details if there is any process of MultiCharts that stays open even after closing all MultiCharts applications.
After closing the application, it waits for all processes to be closed independently by the Task Manager.
If, in a certain period of time, the processes are not closed, the installation of MultiCharts may be corrupted or there may be some corrupted file in the application database.