I'm curious, how did you establish the Postgres connection?
The commercial devart plugin [3] looks pretty neat too but I haven't used it yet
I've also tried the JDBC connectivity option too [4], but with some different use-cases in mind for Postgres (not about Excel)
[1] https://datacornering.com/how-to-connect-to-postgresql-datab...
[2] https://www.postgresql.org/download/products/2-drivers-and-i...