Has anyone encountered an event where business rules don't work?

[sugi1]

I created a Request Item from the ServicePortal's service catalog, and created a process for the WorkFlow Editor to set the Assignment Group to the Request Item.
Business rules that work when the WorkFlow Editor sets a Request Item's Assignment Group may not work.
The frequency is 1 in 7 times. Most of the time, business rules work.
I set the log in the business rule, but it was not a processing problem in the business rule, but the business rule itself was not working.

If any of you ServiceNow techs have faced a situation where business rules aren't working like I did, please give me some advice.

[Tony Chatfield1]

Hi, I would expect a BR to always run if conditions are met,
unless other code was disabling BR's or workflow with setWorkflow(false);

[sugi1]

I agree.
However, although it is recorded in the sys_audit table, the business rule that outputs the log was not working.
Even if the conditions of the business rules are met, there must be times when the business rules do not work.