Facility and Severity not set correctly

[MahdiAlizadeh-TomTom]

• Version:
• Operating System: CentOS 8
• Config File (if you have sensitive info, please remove it):
  logstash.conf.txt
• Sample Data:
  VPN-syslog.txt

I forwarded syslog messages from Rsyslog to Logstash and I want to use "logstash-output-syslog" output plugin in Logstash to forward the events to another syslog server. The issue is that I set the facility to "local0" in logstash but I get the other facility (i.e., alert) in the receiver. The plugin works properly for some facilities though (e.g., mail). I attached my Logstash config file and sample syslog event to the issue.