We've found a problem backing up some of our schemas from pgAdmin4. After some investigation, we've found the problem being the schema names need ident quoting - apparently because they contain capital letters.
For example, pgAdmin generated this code which fails:
$ /usr/bin/pg_dump --file "testera" --host "/var/run/postgresql" --port "5432" --username "postgres" --no-password --verbose --format=c --blobs --schema "HR00000000001-2019" "nubes" pg_dump: last built-in OID is 16383 pg_dump: no matching schemas were found
However, if I quote the schema name by adding a pair of single quotes...
...it works fine. So it seems schema names should be automatically quoted (similar to quote_ident()) for backup to work properly. I guess this is a bug in pgAdmin4 (version I have is 4.11).