For PostgreSQL source semantic model failing but dataflow refreshing successfully

Getting below error while refreshing semantic model for which we are using Postgresql source

Getting below error while refreshing semantic model for which we are using Postgresql source

DataSource.Error: An error happened while reading data from the provider: 'The remote certificate is invalid according to the validation procedure.'. Microsoft.Data.Mashup.ErrorCode = 10434. DataSourceKind = PostgreSQL.

As per official document gateway is mandatory to connect PostgreSQL which is hosted on AWS server.

But for the same source dataflow is working fine without any gateway for the same source.

As the PostgreSQL is hosted on cloud so semantic model must be refresh without gateway.