The Allow users to order items in this view? is an option within SharePoint that allows users to change the order of items within a list.
You migrate a list view with Allow users to order items in this view? set as Yes, and the items in the list are not in the same order in the destination as they were in the source.
The customization of a list views with Allow users to order items in this view? set as Yes, is not supported by the ShareGate migration tool. The app will not preserve the set list order.
There is no solution or workaround to this issue, you will need to reset your prefered order manually at the destination of your migration.