Hi @Khristian Dave Poleracio , Thanks for providing additional information.
Apologies for the inconvenience as this is a known issue with DMS, you can’t use that checkbox with a Single Server source since we have no way to obtain superuser permissions to change it to read-only. Instead, you can use the portal and put the server into read-only mode yourself (via the read_only server parameter), prior to running the migration.
There was an update done where DMS removes the option to set the server to read-only when the project is configured with a Single Server source from the DMS portal.
Hope this information helps. Please let us know if any further queries.