High CPU usage issue when data input or import with bulk load

DHIS2 System

Software = 2.37.7.1
Java version = 11.0.16
Postgresql version = 13
Memory = 36 G
Postgresql = 16G
DHIS2 = 16 G
Ubuntun 20.04 = 4 G

CPU Core = 4

Shared_buffer = 4GB

Work_mem = 20MB

Maintainance_work_mem = 1GB

Effective_cache_size = 11GB

-Xmx16G –Xms16G

We try to import 10 data entry rows to dhis2 event capture program via bulk load.

It was successful .

After few minutes , CPU spike to 100 % .

After 15 minutes CPU back to normal level.

No service interruption.

With data entry more than 200 rows , dhis2 crash.

Please advise.

Is it related to disable program rule engine at back end?

event capture program has 66 program rules.

If yes, how to disable.

Or is there any other issues.

Bulk load version = 3.19.1