We initiated an investigation after receiving a report on the delayed log monitoring of Agent2.

The issue was that Agent2 was sending only 50 lines of logs at a time, regardless of the MaxLinesPerSecond setting.
It was actually affected by BufferSize. (BufferSize=100 / 2)

This result differs from the behavior of the C-based Zabbix Agent. The issue does not present when using the 'EnablePersistentBuffer=1' option in Zabbix Agent 2.

If you set the BufferSize=2 and test the log, you can easily check this issue. only 1 line of the log is being sent at a time.