After the migration is finished, you may need to manually reindex your Magento site to:
- Show categories and products on the storefront
- Show product attributes on the backend
Please follow the steps below to reindex your site:
- Login to your Magento web server via SSH. You can use Putty or any SSH client
- Go to your Magento website folder, then run the commands below:
bin/magento indexer:reindex
bin/magento cache:clean
After the commands are successfully executed, products and attributes will display properly on your Magento site.
Fore more details, please read their instruction at: Manage the indexers on Magento.