Why does syslog data delay when setting no_priority_stripping=true?

[matoulas]

Hi,

When I set no_priority_stripping = true in input.conf in Splunk server, my syslog data send to Splunk work but a very long delay of time.
When I remove no_priority_stripping = true from input.conf. My unit sends syslog to Splunk in real-time.
I do need to set no_priority_stripping = true, in order for me to use syslog_priority.csv lookup table.

I need help to resolve this issue. Can you please point me in the right direction?

Thanks,
Matoula Senethavong