I have the same error, my idea is using command line to find the error
1. logging to postgresql
sudo su - postgres
-bash-4.2$ pg_dump od15_br220805 | gzip > od15_br220805.gz
pg_dump: server version: 13.9; pg_dump version: 9.2.24
pg_dump: aborting because of server version mismatch
-bash-4.2$ exit
##so obviously is the pg_dump version not matched to the server version
2. change the pg_dump version
pg_dump --version
## pg_dump (PostgreSQL)9.2##
sudo find / -name pg_dump
## /usr/bin/pg_dump ##
## /usr/pgsql-13/bin/pg_dump ##
sudo ln -sfn /usr/pgsql-13/bin/pg_dump /usr/bin/pg_dump
pg_dump --version
## pg_dump (PostgreSQL) 13.9 ##
Finally I upgrade the pg_dump
now I could backup the postgresql database either from odoo database manager and command line
Was this ever resolved? I am having the same issues restoring a backup.