When running the Pre-Check Report, the ShareGate migration tool displays the following message:
There are several issues that can be found after running a Pre-Check Report that would not necessarily prevent the copy of item. For example, if the site template used by the site that you would like to copy cannot be found on your destination server, the ShareGate migration tool will automatically fallback on the default site template. Since you may find minor differences between your source and destination after the copy is complete, the app will flag it for you in the report so you have the option to fix the issue before running your migration.
Note: Items that are listed under Other warnings will still be migrated when you attempt to perform the actual copy.
Since these warnings will not prevent the item from copying, there is no definitive solution. You can investigate these on a case-by-case basis and determine if steps should be taken to fix these issues before you start the actual migration. You can get more information by verifying your warnings in the Pre-Check Report.