SharePoint sites not working after database restore from Production to DR

Question

What is the correct way to move sites from production to DR? I followed these steps but it didn't work.

1. Took backup using Backup-SPSite on production
2. Restored site on DR using Restore-SPSite and it worked fine
3. Then I took WSS_Content backup from SQL Server and restored it on DR SQL Server. This DB exists on both Production and DR and it contain the site I migrated above.
4. After restore on DR, site is not working. In View Site Collections in CA, it is showing blank like in screenshot below.

So, SharePoint site backup is working but SQL Server backup is not working? SharePoint is 2016 and SQL Server is 2019.