Cutting and pasting the cord in VisualStudio 2019 will return more than you need.

VisualStudio 2019 Community, C#

When you create an event such as a button in the GUI and cut and paste the code of the event to move it to another location, the code is much older than you need.
Some parts have nothing to do with the event.

It may also occur when cutting code other than events.

I'm too scared to reproduce it, but it has occurred more than five times in the past.
Recently, I have copied, pasted, and finally erased unnecessary code.
Then it doesn't seem to happen.

Is it possible to prevent the code from returning without permission in the setting items?
Also, I would like to know when the code will be returned without permission.

Also, I know that if you change the form name in the GUI, a dialog such as "Do you want to change all the codes to new form names?" will be displayed.
However, in this case, the dialog does not appear and the code returns on its own.

Sorry for the lack of vocabulary and difficulty in understanding.