See:

Here, we are starting graphql-engine using --database-url, the issue with this is that if someone is upgrading from v1.3.3, then the connection string goes into the 2.0 metadata as raw string. See #7270

We should fix this with perhaps starting graphql-engine as:

HASURA_GRAPHQL_DATABASE_URL="$HASURA_GRAPHQL_MIGRATIONS_DATABASE_URL" graphql-engine serve

i.e. load the env instead of --database-url