significant jump in sql statement timing for on server vs a remote connection

Hi all;

We are debugging a sql performance issue. We have a sql file with 50,000
simple select statements in it. If I run the file locally it completes
in less than 15sec.  If I force the local connection to be a tcp/ip
connection via psql -h and I get approximately the same results, 15 - 16sec.

However if we move the file to another server in the same network and
run with a psql -h then it runs for more than 10min. Are there any
postgres specific issues / settings / connection overhead  we should
look at? Or is this simply a network issue and fully outside the scope
of the postgres database?

FYI:

postgresql 13

1.5TB of RAM

512GB of buffer_pool

10GB of work_mem

Thanks in advance