Certain fields will become sticky when information is modified by a user or administrator. Stickiness prevents automatic changes via an SIS Import. If you do not wish to modify the name, or other fields, manually, you can override the changes.
In Global Navigation, click the Admin link  and navigate to your account . Then, in Account Navigation, click the SIS Import link .
Choose your file that has the imported CSV using the Choose File button .
Before starting the import, click the Override UI changes checkbox . This will allow the import to modify the sticky fields.
You may also consider clicking the Clear UI-changed state checkbox as well , this will make any fields affected by the current SIS Import modifiable in the future without using the Override UI changes checkbox.
To start the import, click the Process Data button .
Prevent Users from Modifying their Name
If you use an automated system to import data from a Student Information system, you may want to consider restricting users from modifying their name directly in Canvas.
In Global Navigation, click the Admin link  and navigate to your account . In Account Navigation, click the Settings link .
In Account Settings, scroll to the Features section.
Disable the Users can edit their own name feature .