Some other info: pgbouncer is on the webserver in a normal port (5432). So, from lsmb's point of view, pgbouncer just like a standard postgresql server.
I set lsmb to connect directly to the remote database, just to see, how it works: it is working fine, replication also working well (streaming replication), so, this could be a workaround until we can solve or drop pgbouncer.
So, regarding the pgbouncer, it seems the DBD::Pg, prepared statement and connections has issues, as wrote on cpan.org
. Maybe there are some workarounds, I search the internet...