Postgres stack - can't connect to LB

Hi all,
I’ve got 2 hosts, 1 with a basic app and 1 with Postgres stack (installed from community catalog). Postgres stack consists of load balancer container and db instance container, and here is the issue: if I try to connect to Postgres via LB, I’m getting error “psql: received invalid response to SSL negotiation: H”. However connecting directly to PG instance is OK. What can be the cause and where to dig further?

Found the issue and solution here: