pg_cron uses wrong certificate for authentification

Hello,
we set up our postgres db to work with certificates as authentification instead of password.
This works perfectly fine beside the pg_cron.

The error message we get is:
`provided user name (pgcron_user) and authenticated user name (postgres) do not match`
For me it looks like the pg_cron user is not really used to execute the jobs, because postgres try to verify the user name with the certificate from the postgres user.

Our configuration:

For postgres user, certificates with the CN postgres
/home/postgres/.postgres/postgresql.crt
/home/postgres/.postgres/postgresql.crt
pg_hba entry:
hostssl db postgres 192.168.5.5/32 cert

For pg_cron, certificates with the CN pgcron_user
/home/pgcron_user/.postgresql/postgresql.crt
/home/pgcron_user/.postgresql/postgresql.key
pg_hba entry:
hostssl db pgcron_user 192.168.5.5/32 cert

The jobs are configured with nodename 192.168.5.5 and username: pgcron_user

Any hints or ideas what I can do or check?
Do you need more informations?
Is there a way to set the path to the certificates for pg_cron?

Regards and thx for any help,
Yufiel